Section front
Boilers and heat pumps
Gas work in any home is for a Gas Safe registered engineer. These pages cover what to ask for and what the rules expect when heating in an older house changes.
Replacing the boiler in an older Cambridge terrace
Boiler replacement in a terraced house normally means a 92% efficient appliance, a flushed system, scale treatment in hard water and a carbon monoxide alarm, with all gas work done by a Gas Safe registered engineer.
Longer pieces
Combi or cylinder: three checks for an older house
Combi or system boiler in an old house comes down to three checks: incoming water pressure, the space you can give up, and how hard water will be treated. No single answer suits every older home.
Heat pump in a Victorian terrace: the checks that matter
A heat pump in a Victorian house depends on heat loss, radiator size, a 55°C design point and where the outdoor unit can legally go. Listed status or a conservation area can change that last answer.
Boiler Upgrade Scheme grants for older Cambridge homes
The Boiler Upgrade Scheme gives £7,500 towards an air-to-water or ground source heat pump, £9,000 in eligible off-gas homes until 31 March 2027. No special rule for older homes appears, and insulation is advised, not required.
Old radiators, sludge and what a heating system needs
Old radiators and sludge are usually dealt with by flushing the circuit and adding inhibitor. Approved Document L asks for both before a new heating appliance goes in, commissioned to BS 7593. Radiator size is a separate question.
Check a Gas Safe engineer before gas work starts
A Gas Safe Register check takes two steps: read both sides of the engineer's ID card, then confirm the number with the register on 0800 408 5500. The back of the card shows which work they can do.
In brief
Gas smell or carbon monoxide alarm: get out, then call
Smell gas? No switches, no flames, open doors and windows, leave the building and call 0800 111 999 from outside. For a carbon monoxide alarm, get everyone out and make the same call from outside.
Boiler flue position and plumes in terraced streets
Boiler flue position regulations require outlets that let combustion products disperse; Approved Document J gives Diagrams 34 and 35 as one way to comply. A Gas Safe registered engineer decides the position on the job.
Frozen condensate pipe: what you can safely do
A frozen condensate pipe can often be thawed with warm, not boiling, water, but only on the outside plastic pipe and only from the ground. Stay off ladders, keep the boiler casing shut and call an engineer if unsure.
The boiler controls a new combi has to come with
Under the boiler controls rules, a new gas combi in an existing home needs one of four extras: flue gas heat recovery, weather compensation, load compensation, or a smart thermostat with automation and optimisation.