A gas fire boiler is a heating appliance that combines a gas fire for space heating and a boiler for hot water andor central heating The term can refer to a few different systems depending on context but heres a breakdown of what it might mean Types of Gas Fire Boilers 1 Back Boiler Unit BBU A traditional setup now mostly phased out A boiler is fitted behind a gas fireplace Heats water for central heating and domestic use Common in UK homes from the 1960s1990s Example Baxi Bermuda 2 GasFired Combi Boiler More modern and efficient Provides instant hot water and heating without a tank Usually wallmounted and separate from a fire 3 HighEfficiency Condensing Boilers Burns gas to heat water but uses waste heat for greater efficiency Can be used with radiators or underfloor heating How It Works Back Boiler Style Gas fire heats a heat exchanger behind it Heat is transferred to water in a sealed unit Heated water is pumped through radiators andor to hot taps Pros Spacesaving for older homes Can be costeffective in smaller properties Combined heating and hot water in one unit Cons Old models are inefficient compared to modern condensing boilers Many are noncompliant with modern regulations Can be costly to repair or replace Fire and boiler combo means more wear and tear Modern Replacement Options If youre looking to replace a gas fire boiler especially a back boiler Gas Combi Boiler Electric Fire is a common upgrade Consider air source heat pumps or hydronic heating systems for greener alternatives Look for Boiler Upgrade Scheme UK or local grants if available