---

boiler → ReceivesAction → installed	0.82
boiler → ReceivesAction → repaired	0.78
boiler → ReceivesAction → serviced	0.75
condensing boiler (subgroup of boiler) → HasProperty → more efficient	0.75
boiler → CapableOf → provide hot water	0.74
boiler → CapableOf → heat the water	0.73
boiler → ReceivesAction → replaced	0.73
boiler → HasProperty → old	0.73
conventional boiler (subgroup of boiler) → HasProperty → suitable	0.72
boiler → CapableOf → use natural gas	0.71
new boiler (subgroup of boiler) → HasProperty → efficient	0.70
new boiler (subgroup of boiler) → ReceivesAction → installed	0.69
boiler → CapableOf → use gas	0.69
boiler → CapableOf → produce hot water	0.69
boiler → HasProperty → efficient	0.69
boiler → CapableOf → run on oil	0.68
boiler → ReceivesAction → run on natural gas	0.68
gas boiler (subgroup of boiler) → CapableOf → use gas	0.68
system boiler (subgroup of boiler) → CapableOf → provide hot water	0.68
boiler → CapableOf → use oil	0.67
new boiler (subgroup of boiler) → ReceivesAction → required to be high-efficiency condensing	0.66
boiler → ReceivesAction → maintained	0.66
boiler → ReceivesAction → fueled with oil	0.66
boiler → HasA → an energy-efficiency rating	0.65
boiler → CapableOf → make noise	0.65
boiler → CapableOf → heat up the water	0.65
boiler → CapableOf → heat radiator	0.64
boiler → ReceivesAction → run on gas	0.64
boiler → ReceivesAction → registered within 30 days of installation	0.63
system boiler (subgroup of boiler) → CapableOf → come with a water cylinder	0.62
boiler → ReceivesAction → made	0.62
boiler → ReceivesAction → built	0.62
boiler → ReceivesAction → designed	0.62
boiler → CapableOf → come in many different sizes	0.61
electric boiler (subgroup of boiler) → CapableOf → generate heat	0.61
boiler → CapableOf → come in gas	0.61
gas boiler (subgroup of boiler) → ReceivesAction → likely to be the cheapest heating option	0.61
boiler → ReceivesAction → filled with water	0.61
combi boiler (subgroup of boiler) → HasProperty → compact	0.61
boiler → HasProperty → full	0.60
combi boiler (subgroup of boiler) → ReceivesAction → installed	0.60
efficiency (aspect of boiler) → ReceivesAction → expressed as a percentage consumer group	0.60
boiler → HasProperty → compatible	0.60
boiler → ReceivesAction → manufactured	0.60
boiler → CapableOf → last up to 15 years	0.60
new boiler (subgroup of boiler) → IsA → £2,300	0.60
boiler → ReceivesAction → monitored for emission monitoring	0.59
boiler → HasProperty → good	0.59
combi boiler (subgroup of boiler) → CapableOf → provide hot water	0.59
electric boiler (subgroup of boiler) → ReceivesAction → easy to control	0.59
boiler → HasProperty → essential	0.59
combi boiler (subgroup of boiler) → IsA → central heating boiler	0.59
boiler → ReceivesAction → vented into masonry chimneys	0.59
new boiler (subgroup of boiler) → CapableOf → come with cover	0.59
boiler → HasProperty → reliable	0.59
boiler → CapableOf → come with warranty registration	0.58
boiler → HasProperty → inefficient	0.58
boiler → ReceivesAction → made equal	0.58
boiler → HasProperty → operational	0.58
combi boiler (subgroup of boiler) → HasA → the minimum of moving parts	0.58
electric boiler (subgroup of boiler) → HasProperty → efficient	0.58
system boiler (subgroup of boiler) → ReceivesAction → used in average-sized homes	0.58
electric boiler (subgroup of boiler) → CapableOf → store hot water	0.58
boiler → ReceivesAction → easy to install	0.57
boiler → ReceivesAction → broken	0.57
boiler → CapableOf → work at peak efficiency	0.57
combi boiler (subgroup of boiler) → CapableOf → heat hot water	0.56
boiler → ReceivesAction → commissioned to the highest possible standard	0.56
combi boiler (subgroup of boiler) → CapableOf → act as a water heater	0.56
system boiler (subgroup of boiler) → IsA → good choice	0.56
boiler → HasA → part	0.56
boiler → ReceivesAction → done to high standard	0.56
boiler → ReceivesAction → fueled by coal	0.56
combi boiler (subgroup of boiler) → HasProperty → great	0.56
boiler → CapableOf → live to the hype	0.56
boiler → CapableOf → come with a one-year warranty	0.56
boiler → CapableOf → burn wood pellets	0.56
boiler → IsA → closed vessel	0.56
boiler → AtLocation → warranty	0.56
new boiler (subgroup of boiler) → CapableOf → condense type	0.55
boiler → HasProperty → compliant	0.55
boiler → CapableOf → last between 1-10 years	0.55
boiler → CapableOf → save money	0.55
boiler → AtLocation → the kitchen	0.55
boiler → HasProperty → more suited	0.55
boiler → CapableOf → do the job	0.55
boiler → HasProperty → more powerful	0.55
electric boiler (subgroup of boiler) → HasProperty → more suitable	0.54
boiler → ReceivesAction → assembled	0.54
boiler → ReceivesAction → supplied with minimum one year guarantee	0.54
boiler → CapableOf → use solid waste	0.54
boiler → ReceivesAction → required to be condensing boilers	0.54
boiler → CapableOf → provide steam	0.54
boiler → CapableOf → conform to same safety and efficiency standards	0.54
boiler → HasProperty → larger	0.54
condensing boiler (subgroup of boiler) → CapableOf → ensure higher performance condensing boilers	0.53
electric boiler (subgroup of boiler) → CapableOf → provide viable alternative	0.53
boiler → CapableOf → produce heat	0.53
new boiler (subgroup of boiler) → IsA → 88% efficient	0.53
boiler → HasA → continuous pilot light	0.53
combi boiler (subgroup of boiler) → IsA → easier to install	0.53
condensing boiler (subgroup of boiler) → CapableOf → recover more heat	0.53
electric boiler (subgroup of boiler) → CapableOf → heat floor	0.53
boiler → HasProperty → dangerous	0.53
boiler → ReceivesAction → installed in the uk	0.53
new boiler (subgroup of boiler) → ReceivesAction → to be installed in same place	0.53
system boiler (subgroup of boiler) → HasProperty → perfect	0.53
boiler → HasProperty → quiet	0.53
efficiency (aspect of boiler) → HasProperty → as much as 40%	0.53
efficiency (aspect of boiler) → HasProperty → lower	0.53
new boiler (subgroup of boiler) → HasProperty → a-rated	0.53
electric boiler (subgroup of boiler) → ReceivesAction → placed in operation	0.53
new boiler (subgroup of boiler) → IsA → good option	0.52
boiler → HasA → fireclay	0.52
boiler → HasA → masonry liner	0.52
boiler → HasA → retrofitted metal flue liner	0.52
boiler → ReceivesAction → replaced after every 15 years	0.52
boiler → ReceivesAction → put into use	0.52
boiler → ReceivesAction → sold on the market	0.52
new boiler (subgroup of boiler) → ReceivesAction → designed with the user	0.52
boiler → ReceivesAction → cleaned	0.52
electric boiler (subgroup of boiler) → CapableOf → use electricity	0.52
boiler → CapableOf → serviced on regular basis	0.52
boiler → CapableOf → last many years	0.52
combi boiler (subgroup of boiler) → HasPrerequisite → less space	0.51
boiler → ReceivesAction → removed	0.51
gas boiler (subgroup of boiler) → CapableOf → become more energy-efficient	0.51
boiler → ReceivesAction → used to generate steam	0.51
boiler → MadeOf → stainless steel	0.51
boiler → ReceivesAction → tested	0.51
boiler → HasProperty → safe	0.51
system boiler (subgroup of boiler) → CapableOf → cost $1,500	0.51
boiler → HasPrerequisite → a pressure of 1.3 bar	0.51
boiler → HasPrerequisite → replacement	0.51
boiler → HasPrerequisite → attention	0.51
combi boiler (subgroup of boiler) → HasProperty → more efficient	0.51
boiler → CapableOf → circulate hot water	0.50
boiler → HasProperty → hot	0.50
boiler → HasA → reputation	0.50
boiler → CapableOf → operate on an a-rating efficiency level	0.50
system boiler (subgroup of boiler) → CapableOf → ensure a supply of hot water	0.50
new boiler (subgroup of boiler) → CapableOf → make for substantial expenditure	0.50
boiler → HasProperty → applicable	0.50
boiler → ReceivesAction → created	0.50
boiler → HasPrerequisite → some type of fuel	0.50
boiler → CapableOf → remained committed	0.50
boiler → AtLocation → cupboard	0.50
boiler → CapableOf → use more fuel	0.49
boiler → ReceivesAction → likely to break	0.49
boiler → CapableOf → fit into existing boiler house	0.49
boiler → IsA → vessel	0.49
condensing boiler (subgroup of boiler) → HasA → larger heat exchanger	0.49
boiler → CapableOf → make strange noises	0.49
combi boiler (subgroup of boiler) → IsA → quicker to install	0.49
boiler → CapableOf → cost more money	0.49
boiler → ReceivesAction → recognized for ultra-quiet operation	0.49
boiler → HasProperty → dependable	0.49
system boiler (subgroup of boiler) → CapableOf → heat up a tank of hot water	0.49
boiler → ReceivesAction → built in the united states	0.49
boiler → ReceivesAction → fired	0.48
boiler → DefinedAs → their fuel type	0.48
boiler → ReceivesAction → burned	0.48
boiler → ReceivesAction → sealed	0.48
boiler → HasA → a pressure gauge	0.48
boiler → ReceivesAction → fitted into standard kitchen cupboard	0.48
boiler → CapableOf → lose their efficiency	0.48
electric boiler (subgroup of boiler) → ReceivesAction → reserved for industrial and commercial applications	0.48
boiler → CapableOf → come with information	0.48
boiler → ReceivesAction → placed	0.48
new boiler (subgroup of boiler) → CapableOf → fit into a home condensing boilers	0.48
condensing boiler (subgroup of boiler) → CapableOf → utilise wasted heat	0.48
boiler → CapableOf → store hot water	0.48
boiler → CapableOf → work right time	0.48
system boiler (subgroup of boiler) → CapableOf → differ in important respects	0.48
system boiler (subgroup of boiler) → IsA → sealed system	0.48
boiler → CapableOf → work by heating water	0.48
boiler → HasProperty → big	0.47
efficiency (aspect of boiler) → ReceivesAction → calculated to an industry standard	0.47
efficiency (aspect of boiler) → ReceivesAction → reflected by the maintenance	0.47
boiler → CapableOf → end up wasting over half of the gas	0.47
boiler → CapableOf → fill in the form	0.47
boiler → HasProperty → cold	0.47
new boiler (subgroup of boiler) → CapableOf → condense with larger heat exchanger	0.47
boiler → ReceivesAction → shut down for repair	0.47
electric boiler (subgroup of boiler) → CapableOf → use resistance heating elements	0.47
boiler → ReceivesAction → situated on outside wall	0.47
asbestos → AtLocation → boiler	0.47
new boiler (subgroup of boiler) → ReceivesAction → installed for less than £1,000	0.47
electric boiler (subgroup of boiler) → HasProperty → quiet	0.46
gas boiler (subgroup of boiler) → CapableOf → produce products of combustion	0.46
efficiency (aspect of boiler) → HasProperty → higher	0.46
boiler → ReceivesAction → connected into system	0.46
boiler → CapableOf → replace in emergency	0.46
boiler → CapableOf → serviced on annual basis	0.46
electric boiler (subgroup of boiler) → IsA → large water tank	0.46
new boiler (subgroup of boiler) → HasPrerequisite → polypropylene	0.46
conventional boiler (subgroup of boiler) → HasPrerequisite → a storage tank/water cylinder	0.46
boiler → ReceivesAction → constructed as a body of three chambers	0.46
efficiency (aspect of boiler) → CapableOf → drop to 86%	0.46
boiler → ReceivesAction → combined with thermostat	0.46
system boiler (subgroup of boiler) → IsA → economical choice	0.45
boiler → ReceivesAction → reheated	0.45
boiler → ReceivesAction → responsible for distributing heat	0.45
boiler → CapableOf → run the most common fuel types	0.45
boiler → ReceivesAction → prone to lockouts from time	0.45
boiler → ReceivesAction → appraised on a productivity scale	0.45
boiler → HasPrerequisite → high capacity	0.45
combi boiler (subgroup of boiler) → ReceivesAction → connected to the mains water supply	0.45
conventional boiler (subgroup of boiler) → HasA → separate expansion tank	0.45
conventional boiler (subgroup of boiler) → ReceivesAction → connected to the boiler	0.45
new boiler (subgroup of boiler) → HasPrerequisite → stainless steel new venting	0.45
boiler → HasPrerequisite → hot and cold water tanks	0.45
condensing boiler (subgroup of boiler) → CapableOf → happen with traditional boilers	0.45
electric boiler (subgroup of boiler) → IsA → affordable option	0.45
efficiency (aspect of boiler) → ReceivesAction → improved	0.45
combi boiler (subgroup of boiler) → IsA → high efficiency water heater	0.45
combi boiler (subgroup of boiler) → IsA → a heating system	0.45
boiler → HasProperty → a-rated	0.45
boiler → AtLocation → the loft	0.45
electric boiler (subgroup of boiler) → HasProperty → more eco-friendly	0.44
new boiler (subgroup of boiler) → IsA → complex decision	0.44
new boiler (subgroup of boiler) → HasPrerequisite → water treatment	0.44
new boiler (subgroup of boiler) → IsA → cast aluminum	0.44
combi boiler (subgroup of boiler) → CapableOf → bring cost-effectiveness	0.44
boiler → CapableOf → lose pressure	0.44
gas boiler (subgroup of boiler) → CapableOf → burn more units of gas	0.44
boiler → HasProperty → automatic	0.44
conventional boiler (subgroup of boiler) → CapableOf → take up more space	0.44
boiler → CapableOf → provide domestic hot water	0.44
boiler → CapableOf → break down to time	0.44
boiler → CapableOf → provide several decades of reliable use	0.44
boiler → ReceivesAction → dismantled	0.44
boiler → CapableOf → use radiator	0.44
condensing boiler (subgroup of boiler) → ReceivesAction → designed to make better use of the heat	0.44
boiler → CapableOf → undergo wear	0.44
boiler → ReceivesAction → used in factory	0.44
boiler → ReceivesAction → installed by someone	0.44
boiler → CapableOf → burn straw	0.44
boiler → MadeOf → corrosion resistant copper	0.44
boiler → CapableOf → use coke	0.44
boiler → ReceivesAction → pressurised	0.44
boiler → CapableOf → work to fill radiator	0.44
new boiler (subgroup of boiler) → HasProperty → pricey	0.44
boiler → HasA → an income of below £16,010	0.44
boiler → CapableOf → work at time	0.44
gas boiler (subgroup of boiler) → ReceivesAction → repaired on same visit	0.43
condensing boiler (subgroup of boiler) → CapableOf → make more of the energy	0.43
boiler → HasProperty → asleep	0.43
boiler → HasProperty → more awkward	0.43
boiler → CapableOf → get hold of them	0.43
boiler → CapableOf → operate at correct gas pressure	0.43
boiler → DefinedAs → capacity	0.43
new boiler (subgroup of boiler) → CapableOf → save money	0.43
electric boiler (subgroup of boiler) → HasProperty → more compact than gas boilers	0.43
condensing boiler (subgroup of boiler) → CapableOf → help to save money	0.43
boiler → ReceivesAction → set	0.43
boiler → HasProperty → clean	0.43
boiler → HasProperty → the most energy efficient	0.43
boiler → ReceivesAction → used to heat building	0.43
boiler → AtLocation → the basement	0.43
boiler → HasProperty → for the ultimate	0.43
boiler → HasProperty → fine	0.43
new boiler (subgroup of boiler) → ReceivesAction → completed	0.43
electric boiler (subgroup of boiler) → HasProperty → lighter	0.43
electric boiler (subgroup of boiler) → HasProperty → less expensive	0.43
conventional boiler (subgroup of boiler) → ReceivesAction → expensive to install	0.42
boiler → CapableOf → meet increased demand	0.42
boiler → HasPrerequisite → work	0.42
boiler → CapableOf → used in united kingdom	0.42
boiler → HasProperty → at most vulnerable	0.42
boiler → ReceivesAction → fueled in a few different ways	0.42
boiler → DefinedAs → closed vessel	0.42
boiler → CapableOf → leak water	0.42
gas boiler (subgroup of boiler) → CapableOf → emerge as the most common choice	0.42
gas boiler (subgroup of boiler) → CapableOf → offer a 10 year parts	0.42
gas boiler (subgroup of boiler) → CapableOf → set the standard	0.42
gas boiler (subgroup of boiler) → ReceivesAction → expensive to put	0.42
boiler → CapableOf → create real savings	0.42
boiler → HasProperty → durable	0.42
boiler → CapableOf → make up about 30% of all boilers	0.42
boiler → CapableOf → last for year	0.42
boiler → CapableOf → last with routine maintenance	0.42
boiler → HasProperty → tough	0.42
boiler → ReceivesAction → used in hospital	0.42
boiler → CapableOf → leave the house	0.42
combi boiler (subgroup of boiler) → IsA → popular choice	0.42
system boiler (subgroup of boiler) → HasPrerequisite → external tank	0.42
boiler → CapableOf → burn wood chips	0.42
new boiler (subgroup of boiler) → CapableOf → pay in one lump sum	0.42
condensing boiler (subgroup of boiler) → CapableOf → operate at high efficiency levels	0.42
boiler → ReceivesAction → monitored for combustion adjustment	0.42
boiler → ReceivesAction → equipped with the biggest thermoregulation valve esbe	0.42
boiler → ReceivesAction → equipped with strong pump	0.42
boiler → ReceivesAction → equipped with controlled servo-operated three-way valve	0.42
boiler → CapableOf → keep a litre of water	0.42
boiler → HasA → shorter lifespan	0.42
boiler → CapableOf → account for 55 per	0.42
boiler → CapableOf → seen better days	0.42
boiler → HasPrerequisite → the least amount of maintenance	0.42
boiler → CapableOf → act as reliable source of heat	0.42
boiler → ReceivesAction → used in saturated steam	0.42
boiler → ReceivesAction → used in garage	0.42
conventional boiler (subgroup of boiler) → ReceivesAction → referred as only boilers	0.41
efficiency (aspect of boiler) → CapableOf → instal efficient boiler	0.41
boiler → HasA → dial	0.41
boiler → CapableOf → heat home	0.41
combi boiler (subgroup of boiler) → CapableOf → follow same heating process	0.41
boiler → HasProperty → effective	0.41
boiler → CapableOf → give trouble	0.41
boiler → ReceivesAction → installed by company	0.41
boiler → CapableOf → take more time	0.41
boiler → HasA → a combustion chamber	0.41
new boiler (subgroup of boiler) → CapableOf → come with warranty	0.41
new boiler (subgroup of boiler) → ReceivesAction → installed in the uk	0.41
combi boiler (subgroup of boiler) → CapableOf → lose pressure	0.41
combi boiler (subgroup of boiler) → IsA → the most popular type	0.41
boiler → ReceivesAction → serviced in line	0.41
system boiler (subgroup of boiler) → IsA → hybrid	0.41
boiler → CapableOf → provide comfort	0.41
combi boiler (subgroup of boiler) → CapableOf → bring the best of heating efficiency	0.41
combi boiler (subgroup of boiler) → ReceivesAction → suited to smaller homes	0.41
boiler → CapableOf → run on fuel oil	0.41
boiler → CapableOf → last for 30 years	0.41
boiler → ReceivesAction → fitted with equithermal regulation	0.41
boiler → IsA → a pressure vessel	0.41
boiler → CapableOf → warm up for while	0.41
boiler → DefinedAs → application	0.41
boiler → CapableOf → offer more heating	0.41
boiler → ReceivesAction → fitted in last decade	0.41
boiler → HasProperty → uneconomical	0.41
boiler → CapableOf → help prevent problem	0.41
boiler → ReceivesAction → fixed	0.41
gas boiler (subgroup of boiler) → HasPrerequisite → venting	0.41
gas boiler (subgroup of boiler) → HasPrerequisite → additional gas piping	0.41
conventional boiler (subgroup of boiler) → HasA → both a cylinder	0.41
conventional boiler (subgroup of boiler) → HasA → tank	0.41
boiler → CapableOf → run on mains gas	0.40
boiler → ReceivesAction → set to certain temperature	0.40
boiler → ReceivesAction → powered by central gas heating system	0.40
boiler → ReceivesAction → drained	0.40
boiler → ReceivesAction → faced with real-world test conditions	0.40
boiler → ReceivesAction → triggered into action	0.40
boiler → ReceivesAction → switched	0.40
boiler → ReceivesAction → used in laboratory	0.40
boiler → CapableOf → compare the cost of the repair	0.40
boiler → HasProperty → around 55% efficient	0.40
conventional boiler (subgroup of boiler) → IsA → great replacement boiler choice	0.40
efficiency (aspect of boiler) → ReceivesAction → improved by condensing technology modern condensing boilers	0.40
boiler → HasProperty → expensive	0.40
electric boiler (subgroup of boiler) → CapableOf → work under similar principle	0.40
gas boiler (subgroup of boiler) → IsA → remain to be top choice	0.40
combi boiler (subgroup of boiler) → IsA → on constant standby	0.40
boiler → CapableOf → mean lower cost	0.40
boiler → CapableOf → operate at about 50% efficiency	0.40
boiler → CapableOf → cost great deal	0.40
boiler → CapableOf → suit every home	0.40
boiler → CapableOf → combine a water heater	0.40
boiler → IsA → enclosed vessel	0.40
boiler → ReceivesAction → released into the air	0.40
boiler → CapableOf → repaired for fixed price	0.40
boiler → ReceivesAction → classified into following configurations	0.40
boiler → HasPrerequisite → depressurising	0.40
boiler → HasProperty → faulty	0.40
boiler → HasProperty → difficult	0.39
gas boiler (subgroup of boiler) → ReceivesAction → repaired	0.39
boiler → CapableOf → come with hot water tank	0.39
boiler → CapableOf → evaporate the water	0.39
boiler → CapableOf → safeguard the district heating grid	0.39
boiler → CapableOf → preheat the water	0.39
boiler → CapableOf → burn wood	0.39
boiler → CapableOf → distribute hot water	0.39
boiler → HasA → the lsuffix	0.39
boiler → AtLocation → 800 west cesar chavez	0.39
combi boiler (subgroup of boiler) → HasA → right output	0.39
combi boiler (subgroup of boiler) → IsA → difficult task	0.39
combi boiler (subgroup of boiler) → CapableOf → come in various outputs	0.39
combi boiler (subgroup of boiler) → CapableOf → suit semi-detached house	0.39
combi boiler (subgroup of boiler) → AtLocation → cupboard	0.39
boiler → HasA → a 10 years warranty	0.39
boiler → CapableOf → conserve energy	0.39
combi boiler (subgroup of boiler) → CapableOf → provide effective water heating	0.39
efficiency (aspect of boiler) → HasProperty → low	0.39
boiler → HasProperty → warm	0.38
boiler → CapableOf → prevent fire	0.38
boiler → CapableOf → boast intelligent pre-heatsetting	0.38
boiler → CapableOf → heat the property	0.38
boiler → ReceivesAction → sold to hotel	0.38
boiler → ReceivesAction → sold to hospital	0.38
boiler → ReceivesAction → among the most important investments	0.38
boiler → UsedFor → 2.5 of them	0.38
boiler → CapableOf → run on lpg	0.38
boiler → HasA → tankless water heater	0.38
boiler → ReceivesAction → installed by manufacturer trained engineers	0.38
electric boiler (subgroup of boiler) → ReceivesAction → compared to a gas boiler	0.38
electric boiler (subgroup of boiler) → IsA → specialized item	0.38
combi boiler (subgroup of boiler) → IsA → a combi boiler	0.38
combi boiler (subgroup of boiler) → CapableOf → sound like right system	0.38
condensing boiler (subgroup of boiler) → HasProperty → more expensive	0.38
boiler → HasProperty → more friendly	0.38
boiler → DefinedAs → any combination	0.38
boiler → HasProperty → slim	0.38
boiler → CapableOf → produce vapor	0.38
boiler → HasA → sensor	0.38
boiler → ReceivesAction → obtained	0.38
condensing boiler (subgroup of boiler) → CapableOf → produce cool flue gas temperatures	0.38
new boiler (subgroup of boiler) → CapableOf → increase efficiency	0.38
new boiler (subgroup of boiler) → ReceivesAction → cheap to run	0.38
boiler → CapableOf → opt for a combi-boiler	0.38
boiler → CapableOf → react	0.38
boiler → HasProperty → useful	0.38
combi boiler (subgroup of boiler) → ReceivesAction → of high quality	0.38
boiler → CapableOf → come with a 12-year guarantee	0.38
system boiler (subgroup of boiler) → HasProperty → compatible	0.38
system boiler (subgroup of boiler) → HasPrerequisite → cylinder	0.38
system boiler (subgroup of boiler) → ReceivesAction → built into the boiler	0.38
boiler → ReceivesAction → used in conjunction	0.38
gas boiler (subgroup of boiler) → IsA → the most efficient style	0.37
boiler → CapableOf → display an error message	0.37
combi boiler (subgroup of boiler) → ReceivesAction → available in a variety of wattages	0.37
combi boiler (subgroup of boiler) → CapableOf → take care of both the hot water	0.37
combi boiler (subgroup of boiler) → ReceivesAction → installed in a hard-water area	0.37
gas boiler (subgroup of boiler) → CapableOf → replace conventional ones	0.37
electric boiler (subgroup of boiler) → IsA → a convenient process unit	0.37
new boiler (subgroup of boiler) → CapableOf → work with old systems	0.37
boiler → CapableOf → heat on other hand	0.37
boiler → ReceivesAction → used in power plants	0.37
boiler → CapableOf → burn pellet	0.37
boiler → CapableOf → burn other solids	0.37
boiler → ReceivesAction → flushed	0.37
boiler → CapableOf → perform in the coldest days	0.37
boiler → ReceivesAction → installed in most properties	0.37
boiler → MadeOf → durable steel	0.37
boiler → ReceivesAction → examined	0.37
boiler → ReceivesAction → produced in output	0.37
boiler → CapableOf → run great	0.37
electric boiler (subgroup of boiler) → CapableOf → come in a 3 types	0.37
electric boiler (subgroup of boiler) → HasA → different outputs	0.37
electric boiler (subgroup of boiler) → HasProperty → faster	0.37
electric boiler (subgroup of boiler) → CapableOf → pass the water	0.37
boiler → CapableOf → cost 1,500	0.37
boiler → CapableOf → turn off on an overheat fault	0.36
boiler → CapableOf → extract more heat	0.36
boiler → ReceivesAction → fixed by tea time	0.36
boiler → UsedFor → steam locomotives	0.36
boiler → CapableOf → range in price	0.36
boiler → CapableOf → work	0.36
combi boiler (subgroup of boiler) → ReceivesAction → available in three sizes	0.36
electric boiler (subgroup of boiler) → CapableOf → produce gas leaks	0.36
boiler → CapableOf → pose danger	0.36
boiler → CapableOf → start to malfunction	0.36
combi boiler (subgroup of boiler) → IsA → on the scene	0.36
boiler → CapableOf → tolerate high temperatures	0.36
new boiler (subgroup of boiler) → HasA → significant impact	0.36
gas boiler (subgroup of boiler) → CapableOf → save money	0.36
boiler → ReceivesAction → sold	0.36
boiler → HasProperty → open	0.36
boiler → CapableOf → give hard time	0.36
boiler → HasA → burner	0.36
boiler → ReceivesAction → inspected by certified professionals	0.36
boiler → ReceivesAction → tuned	0.36
combi boiler (subgroup of boiler) → ReceivesAction → available in each range	0.35
boiler → ReceivesAction → reset	0.35
boiler → CapableOf → encounter problem	0.35
new boiler (subgroup of boiler) → ReceivesAction → installed by gas safe registered engineer	0.35
new boiler (subgroup of boiler) → ReceivesAction → required	0.35
boiler → CapableOf → increase their efficiency	0.35
boiler → HasProperty → happy	0.35
boiler → Causes → big problems	0.35
boiler → CapableOf → work with radiant heating system	0.35
electric boiler (subgroup of boiler) → CapableOf → become more popular	0.35
boiler → CapableOf → run at full power	0.35
new boiler (subgroup of boiler) → IsA → green way	0.35
boiler → ReceivesAction → run on liquid propane oil-fired models	0.35
boiler → CapableOf → retain condensate water	0.35
boiler → CapableOf → generate high pressure steam	0.35
boiler → ReceivesAction → insulated	0.34
boiler → HasA → a loss of feed water	0.34
condensing boiler (subgroup of boiler) → CapableOf → generate more hot water	0.34
boiler → HasA → high efficiency	0.34
boiler → CapableOf → waste a lot of energy	0.34
boiler → CapableOf → react to outside temperature	0.34
boiler → HasA → few mechanical parts	0.34
gas boiler (subgroup of boiler) → ReceivesAction → fuelled with natural gas	0.34
gas boiler (subgroup of boiler) → ReceivesAction → fuelled with oil	0.34
gas boiler (subgroup of boiler) → ReceivesAction → fuelled with lpg	0.34
gas boiler (subgroup of boiler) → ReceivesAction → fuelled with propane	0.34
gas boiler (subgroup of boiler) → UsedFor → central heating	0.34
new boiler (subgroup of boiler) → ReceivesAction → installed by professional	0.34
electric boiler (subgroup of boiler) → CapableOf → offer wide array of features	0.34
electric boiler (subgroup of boiler) → CapableOf → provide excellent protection	0.34
electric boiler (subgroup of boiler) → ReceivesAction → operated by heavy duty	0.34
electric boiler (subgroup of boiler) → IsA → voltage	0.34
electric boiler (subgroup of boiler) → IsA → circuit breakers	0.34
electric boiler (subgroup of boiler) → IsA → peak load controllers	0.34
electric boiler (subgroup of boiler) → IsA → safety interlocks	0.34
efficiency (aspect of boiler) → ReceivesAction → maintained	0.34
boiler → HasProperty → noisy	0.34
boiler → CapableOf → restore to working order	0.34
boiler → HasProperty → empty	0.34
boiler → ReceivesAction → started	0.34
boiler → ReceivesAction → vented	0.34
boiler → ReceivesAction → filled	0.34
boiler → ReceivesAction → concerned	0.34
boiler → ReceivesAction → rebuilt	0.34
boiler → HasProperty → identical	0.34
boiler → HasA → 2 or 3 3 pressuretrols	0.34
boiler → CapableOf → burn log	0.34
boiler → CapableOf → come in many forms	0.34
boiler → ReceivesAction → classified as high-pressure	0.34
condensing boiler (subgroup of boiler) → HasSubevent → a plumeof vapour	0.33
condensing boiler (subgroup of boiler) → ReceivesAction → backed by national network of service engineers	0.33
boiler → CapableOf → become less efficient	0.33
boiler → HasA → pipe	0.33
boiler → ReceivesAction → unlikely to break	0.33
boiler → CapableOf → work with virtually any baseboard	0.33
combi boiler (subgroup of boiler) → CapableOf → supply busy domestic household	0.33
boiler → ReceivesAction → covered	0.33
efficiency (aspect of boiler) → ReceivesAction → obtained to replace the boiler	0.33
electric boiler (subgroup of boiler) → IsA → need	0.33
new boiler (subgroup of boiler) → HasA → wastage of less than 10p	0.33
boiler → CapableOf → become problematic	0.33
boiler → HasA → certified energy rating	0.33
electric boiler (subgroup of boiler) → HasProperty → competitive	0.33
condensing boiler (subgroup of boiler) → ReceivesAction → fitted to traditional indirect-pressure	0.33
boiler → ReceivesAction → sold to laundry plants	0.32
boiler → ReceivesAction → sold to cruise lines	0.32
boiler → ReceivesAction → sold to nursing homes	0.32
boiler → ReceivesAction → sold to government institutions	0.32
boiler → ReceivesAction → sold to distributor	0.32
boiler → ReceivesAction → sold to specialized users	0.32
boiler → CapableOf → comply with all the current safety regulations	0.32
boiler → ReceivesAction → emptied	0.32
boiler → HasProperty → free	0.32
boiler → CapableOf → heat the fluid	0.32
boiler → HasProperty → adaptable	0.32
boiler → ReceivesAction → sold throughout europe	0.32
boiler → ReceivesAction → superheated	0.32
boiler → ReceivesAction → resolved in the fastest possible time	0.32
boiler → ReceivesAction → fitted by experienced professional	0.32
boiler → ReceivesAction → among the most popular heating systems	0.32
boiler → AtLocation → countryside homes	0.32
boiler → ReceivesAction → classified at risk	0.32
boiler → CapableOf → inspected at regular intervals	0.32
boiler → ReceivesAction → installed in the recess	0.32
boiler → CapableOf → function in safe and efficient manner	0.32
boiler → MadeOf → old material	0.32
boiler → CapableOf → last to century	0.32
boiler → ReceivesAction → built by the most reputable manufacturers	0.32
boiler → CapableOf → come with hidden surcharge	0.32
combi boiler (subgroup of boiler) → CapableOf → become across the uk	0.32
condensing boiler (subgroup of boiler) → CapableOf → eject gas	0.31
boiler → CapableOf → come in oil fuel types	0.31
boiler → HasA → all the components	0.31
boiler → ReceivesAction → installed behind fire	0.31
boiler → CapableOf → activate the water	0.31
boiler → ReceivesAction → installed with plastic condensate pipe	0.31
boiler → ReceivesAction → combined with easy-to-use	0.31
boiler → ReceivesAction → combined with sophisticated controllers	0.31
boiler → ReceivesAction → ideal for larger homes	0.31
boiler → CapableOf → use the app	0.31
boiler → HasA → pre-existing fault	0.31
boiler → CapableOf → 's connected to the water mains	0.31
boiler → CapableOf → give friendly and environmentally friendly service	0.31
electric boiler (subgroup of boiler) → IsA → great combination	0.31
electric boiler (subgroup of boiler) → CapableOf → use gas	0.31
electric boiler (subgroup of boiler) → ReceivesAction → vented	0.31
electric boiler (subgroup of boiler) → IsA → less heat-efficient	0.31
electric boiler (subgroup of boiler) → CapableOf → feature robust design	0.31
electric boiler (subgroup of boiler) → CapableOf → feature wide range of regulation	0.31
combi boiler (subgroup of boiler) → ReceivesAction → given an a	0.31
combi boiler (subgroup of boiler) → IsA → for good reason	0.31
boiler → HasProperty → dry	0.31
boiler → ReceivesAction → fired by diesel	0.31
boiler → ReceivesAction → stoved with high temperature paint	0.31
boiler → ReceivesAction → lagged with individual hardwood planks	0.31
boiler → CapableOf → run on liquid gas	0.31
boiler → HasProperty → intact	0.31
boiler → CapableOf → reduce heat loss	0.31
boiler → ReceivesAction → operated at higher load factor	0.31
boiler → ReceivesAction → developed in recent years	0.31
boiler → CapableOf → undergone several repairs	0.31
boiler → AtLocation → area source facilities	0.31
boiler → CapableOf → shut down the error code	0.31
boiler → CapableOf → provide a more comfortable and heat	0.31
boiler → HasA → better longevity	0.31
boiler → CapableOf → start showing signs of wear and tear	0.31
efficiency (aspect of boiler) → HasProperty → key	0.31
new boiler (subgroup of boiler) → ReceivesAction → needed at a cost of £3,360	0.31
condensing boiler (subgroup of boiler) → ReceivesAction → released	0.30
boiler → HasSubevent → high repair costs	0.30
boiler → CapableOf → fit through standard doorway	0.30
boiler → HasProperty → more harmful	0.30
combi boiler (subgroup of boiler) → HasA → easy-to-use control panel	0.30
combi boiler (subgroup of boiler) → CapableOf → become in past couple of years	0.30
gas boiler (subgroup of boiler) → SimilarTo → a gas furnace	0.30
gas boiler (subgroup of boiler) → ReceivesAction → left unserviced	0.30
boiler → HasProperty → critical	0.30
boiler → ReceivesAction → vented through high-temperature plastic vent pipe	0.30
boiler → ReceivesAction → insulated with special expanded polypropylene eppfoam	0.30
boiler → ReceivesAction → frustrating to deal	0.30
boiler → CapableOf → struggle to keep up with demand	0.30
boiler → CapableOf → make for cost-inefficient process	0.30
boiler → HasProperty → perfect	0.30
boiler → CapableOf → convert over 90% of the fuel	0.30
electric boiler (subgroup of boiler) → HasA → mixed reputation	0.30
electric boiler (subgroup of boiler) → IsA → effective water heating appliances	0.30
electric boiler (subgroup of boiler) → HasProperty → safe	0.30
electric boiler (subgroup of boiler) → HasProperty → clean	0.30
electric boiler (subgroup of boiler) → CapableOf → power central heating	0.30
new boiler (subgroup of boiler) → IsA → worthwhile addition	0.29
boiler → CapableOf → operate in condensing mode	0.29
boiler → ReceivesAction → equipped with modulating burner	0.29
boiler → CapableOf → take up more space	0.29
boiler → CapableOf → eliminate the need	0.29
system boiler (subgroup of boiler) → IsA → better option	0.29
combi boiler (subgroup of boiler) → HasProperty → perfect	0.29
combi boiler (subgroup of boiler) → ReceivesAction → known for energy saving capabilities	0.29
combi boiler (subgroup of boiler) → ReceivesAction → available in several groups	0.29
combi boiler (subgroup of boiler) → ReceivesAction → ideal for small to medium sized properties	0.29
combi boiler (subgroup of boiler) → CapableOf → use the mains water pressure	0.29
boiler → HasA → mechanism	0.29
condensing boiler (subgroup of boiler) → IsA → great heating system	0.29
boiler → ReceivesAction → manufactured within last four decades	0.29
boiler → ReceivesAction → installed with minimum disruption	0.29
boiler → ReceivesAction → covered for whole decade	0.29
boiler → CapableOf → use oil boilers	0.29
boiler → HasProperty → simple	0.29
boiler → HasA → easy-fit front cover	0.29
boiler → ReceivesAction → equipped	0.29
combi boiler (subgroup of boiler) → IsA → compact, economical, use mains pressure	0.28
efficiency (aspect of boiler) → CapableOf → translate to more energy savings	0.28
electric boiler (subgroup of boiler) → CapableOf → produce waste gases	0.28
electric boiler (subgroup of boiler) → ReceivesAction → costly to run	0.28
new boiler (subgroup of boiler) → ReceivesAction → installed to the highest possible standard	0.28
combi boiler (subgroup of boiler) → HasProperty → one such kind	0.28
boiler → CapableOf → build around single design concept	0.28
boiler → ReceivesAction → deemed to be in use	0.27
boiler → HasA → long history	0.27
boiler → CapableOf → work in same way	0.27
boiler → HasProperty → short	0.27
boiler → ReceivesAction → converted to oil	0.27
boiler → CapableOf → produce	0.27
boiler → CapableOf → condense the water vapor	0.27
boiler → CapableOf → supply entire property	0.27
boiler → CapableOf → fire up after set time	0.27
boiler → ReceivesAction → loaded	0.27
boiler → ReceivesAction → used on mobile road	0.27
boiler → ReceivesAction → used on steam boats	0.27
boiler → CapableOf → cope	0.27
boiler → CapableOf → come in shape	0.27
boiler → ReceivesAction → installed with water level	0.27
boiler → CapableOf → fire bituminous coal	0.27
boiler → HasProperty → unique	0.27
boiler → HasProperty → common	0.27
boiler → ReceivesAction → produced as fluid-tight coupling	0.27
boiler → ReceivesAction → repressurised	0.27
boiler → ReceivesAction → equipped with economizer	0.27
boiler → ReceivesAction → made in canada	0.27
boiler → SimilarTo → car	0.27
combi boiler (subgroup of boiler) → CapableOf → grow in popularity	0.27
combi boiler (subgroup of boiler) → CapableOf → meet the highest efficiency standards	0.27
boiler → CapableOf → reduce carbon emissions	0.27
boiler → HasProperty → safer	0.27
boiler → CapableOf → come with expensive repairs	0.27
boiler → CapableOf → break down in the middle of winter	0.27
boiler → ReceivesAction → built to pressure	0.27
boiler → HasA → long life	0.27
new boiler (subgroup of boiler) → AtLocation → the most professional hands	0.26
boiler → CapableOf → reach the very highest efficiency tandards	0.26
electric boiler (subgroup of boiler) → ReceivesAction → manufactured by swedish engineering firm zander	0.26
combi boiler (subgroup of boiler) → CapableOf → feature an air handler interlock	0.26
combi boiler (subgroup of boiler) → IsA → ideal replacement boiler	0.26
combi boiler (subgroup of boiler) → ReceivesAction → known for their convenience	0.26
boiler → ReceivesAction → taken off line	0.26
boiler → CapableOf → work with our boiler service	0.26
boiler → ReceivesAction → damaged	0.26
boiler → CapableOf → become efficient	0.26
efficiency (aspect of boiler) → CapableOf → save money	0.25
efficiency (aspect of boiler) → ReceivesAction → achieved	0.25
boiler → CapableOf → based on the type of noise	0.25
boiler → CapableOf → feature water-cooled rotation chambers	0.25
boiler → ReceivesAction → rated at 25,000 btus	0.25
boiler → CapableOf → serviced in the summer	0.25
boiler → ReceivesAction → available in both combi	0.25
boiler → ReceivesAction → available in heat-only models	0.25
boiler → ReceivesAction → supplied with a choice of flue lengths	0.25
boiler → ReceivesAction → considered normal	0.25
boiler → CapableOf → weigh as much as 165 tons	0.25
boiler → CapableOf → top up the heat	0.25
boiler → ReceivesAction → cycled	0.25
boiler → ReceivesAction → regulated	0.25
boiler → CapableOf → grow in size	0.25
boiler → CapableOf → sustain higher pressure	0.25
boiler → ReceivesAction → fitted with a water gauge	0.25
boiler → ReceivesAction → equipped with fan	0.25
boiler → HasProperty → cool	0.25
boiler → CapableOf → inspect all pipe work	0.25
boiler → CapableOf → run for longer	0.25
boiler → ReceivesAction → due to serviced	0.25
boiler → ReceivesAction → fitted with a sequence controller	0.25
boiler → ReceivesAction → fitted with frame failure device	0.25
boiler → ReceivesAction → customized	0.25
boiler → ReceivesAction → hidden behind chimney	0.25
boiler → ReceivesAction → equipped with a flue gas cooler	0.25
boiler → HasProperty → tall	0.25
boiler → ReceivesAction → used in sugar industries	0.25
boiler → ReceivesAction → controlled by adjustable pressure stat	0.25
boiler → CapableOf → operate at part load	0.25
boiler → ReceivesAction → equipped with multi-clones	0.25
boiler → CapableOf → represent significant capital investment	0.25
boiler → ReceivesAction → installed with three flues	0.25
boiler → MadeOf → cast iron	0.25
boiler → CapableOf → checked by a boiler service	0.25
boiler → CapableOf → reheat returned cool water	0.25
boiler → CapableOf → run on tank gas	0.25
boiler → ReceivesAction → wasted	0.25
boiler → ReceivesAction → used in school	0.25
boiler → HasA → enough ventilation	0.25
boiler → ReceivesAction → made in germany	0.25
boiler → HasA → manhole	0.25
boiler → ReceivesAction → welded	0.25
boiler → CapableOf → work to specification	0.25
boiler → ReceivesAction → staged	0.25
boiler → ReceivesAction → connected in parallel	0.25
boiler → CapableOf → serviced in the winter	0.25
boiler → ReceivesAction → sent for overhaul	0.25
boiler → AtLocation → room	0.25
boiler → CapableOf → feature low water pressure sensor	0.25
boiler → HasProperty → active	0.25
boiler → AtLocation → bridgnorth	0.25
boiler → ReceivesAction → set up in north london	0.25
boiler → CapableOf → mount on exterior wall	0.25
boiler → CapableOf → get hotter	0.25
boiler → ReceivesAction → used on class	0.25
boiler → ReceivesAction → based on other factor	0.25
boiler → ReceivesAction → insulated in weather resistant casing	0.25
boiler → HasPrerequisite → good skim	0.25
boiler → CapableOf → hold larger volume of fuel	0.25
boiler → CapableOf → provide relief	0.25
combi boiler (subgroup of boiler) → HasProperty → more suitable	0.25
combi boiler (subgroup of boiler) → CapableOf → combine central heating boiler	0.25
condensing boiler (subgroup of boiler) → CapableOf → concentrate water vapor	0.25
conventional boiler (subgroup of boiler) → IsA → open systems	0.25
combi boiler (subgroup of boiler) → CapableOf → provide unlimited supply of hot water	0.25
boiler → CapableOf → leak carbon monoxide	0.25
boiler → HasProperty → undersized	0.25
boiler → HasProperty → idle	0.25
boiler → CapableOf → experience problem	0.25
boiler → CapableOf → work at night	0.25
boiler → CapableOf → fail to start for one reason	0.25
home (aspect of homeowner) → HasA → boiler	0.25
electric boiler (subgroup of boiler) → IsA → excellent investment	0.24
electric boiler (subgroup of boiler) → CapableOf → run traditional radiator-based central heating	0.24
boiler → CapableOf → get on in year	0.24
boiler → CapableOf → paraffin heater	0.24
boiler → Causes → unnecessary expenses	0.24
boiler → HasProperty → heavy	0.24
boiler → ReceivesAction → damaged beyond the point of boiler repair	0.24
boiler → ReceivesAction → ruined	0.24
boiler → CapableOf → work for year	0.24
combi boiler (subgroup of boiler) → IsA → smaller than other types	0.23
boiler → CapableOf → last for decade	0.23
boiler → CapableOf → work in the heart of the winter	0.22
boiler → HasProperty → outdated	0.22
boiler → MadeOf → the handle	0.22
boiler → ReceivesAction → built to any steam capacities	0.22
boiler → ReceivesAction → installed in right way	0.22
boiler → CapableOf → function at the peak of their efficiency	0.22
boiler → CapableOf → found less common than gas boilers	0.22
electric boiler (subgroup of boiler) → CapableOf → run wetunderfloor systems	0.22
boiler → CapableOf → leak around pipe	0.22
efficiency (aspect of boiler) → HasProperty → high	0.21
boiler → HasProperty → loud	0.21
boiler → HasProperty → risky	0.21
boiler → CapableOf → reach certain age	0.21
boiler → ReceivesAction → bled	0.21
system boiler (subgroup of boiler) → IsA → easier to install	0.21
boiler → HasA → low pressure	0.19
boiler → ReceivesAction → used in textile plant	0.19
boiler → ReceivesAction → used in food plant	0.19
boiler → ReceivesAction → recommended by the energy saving trust	0.19
boiler → HasProperty → impressive	0.19
boiler → CapableOf → paraffin solid fuel powered stoves	0.19
boiler → CapableOf → take long time	0.19
boiler → HasProperty → bad	0.19
boiler → ReceivesAction → stopped	0.19
boiler → HasProperty → antiquated	0.19
boiler → CapableOf → give up the ghost	0.19
boiler → CapableOf → break down at any time	0.19
boiler → Causes → loss of life	0.19
boiler → CapableOf → pass a series of safety checks	0.19
boiler → CapableOf → maintain to the highest of standards	0.19
boiler → AtLocation → disrepair	0.19
boiler → ReceivesAction → retrofitted	0.18
boiler → ReceivesAction → forced to work more energy	0.16
boiler → CapableOf → operate with fluctuating pressure	0.16
boiler → ReceivesAction → used in paper mill	0.16
boiler → HasProperty → repairable	0.16
boiler → ReceivesAction → powered by 7,200 bushels of corn	0.16
boiler → AtLocation → cold standby	0.16
boiler → ReceivesAction → surrounded by brickwork	0.16
boiler → HasProperty → fatal	0.16
boiler → ReceivesAction → overworked	0.16
boiler → CapableOf → use much oil	0.16
boiler → HasProperty → dirty	0.16
boiler → HasProperty → the largest	0.16
boiler → CapableOf → emit mercury	0.16
boiler → CapableOf → emit cadmium	0.16
boiler → CapableOf → emit particle pollution	0.16
boiler → CapableOf → reach high heating efficiencies	0.16
boiler → HasA → wonderful advantages	0.16
boiler → CapableOf → cost money	0.16
boiler → CapableOf → go strong	0.16
boiler → HasProperty → rugged	0.16
boiler → CapableOf → fire with large pieces of wood	0.16
boiler → CapableOf → invalidate any warranty	0.16
boiler → CapableOf → cost a lot of money	0.16
boiler → CapableOf → collect in the heat exchanger	0.16
boiler → CapableOf → use more gas	0.16
boiler → HasPrerequisite → additional make-up water	0.16
boiler → CapableOf → boost to 34.2 kw	0.16
boiler → Causes → explosion	0.16
boiler → ReceivesAction → connected to the internet	0.16
boiler → CapableOf → come with steel wall-mounting jig	0.16
electric boiler (subgroup of boiler) → HasProperty → 100% efficient	0.16
gas boiler (subgroup of boiler) → HasProperty → unsafe	0.16
new boiler (subgroup of boiler) → ReceivesAction → sited	0.16
boiler → ReceivesAction → equipped with superheater	0.15