Home Boiler repair Belfast
Boiler repair in Belfast
Tell us whether your boiler runs on gas or oil and what it's doing. We pass the job to Gas Safe registered or OFTEC registered engineers who cover your area.
Belfast repair calls split between two fuels. About 71% of homes use gas only and 20% use oil only, and a few thousand have both. Gas faults need a Gas Safe registered engineer and oil faults an OFTEC technician, so say which you have when you book.
Belfast at a glance
- Water hardness
- Varies by supply zone. NI Water's postcode checker gives 43 mg/l as calcium carbonate (soft) in Belfast Ballyhanwood, 67 mg/l (moderately soft) in Belfast Breda South, and about 158 mg/l (moderately hard) in Belfast Oldpark and Dunore Belfast North. The water comes from Lough Neagh, Silent Valley and Dorisland reservoirs in different blends. Source
- Tenure
- 20.5% of Belfast households rented privately in 2021. 16.9% rented from the Northern Ireland Housing Executive and 9.4% from a housing association or charity. Source
- Landlord safety rules
- Northern Ireland landlords must have gas appliances checked every year by a Gas Safe registered engineer, give new tenants the record within 28 days and keep it for two years. Since 1 September 2024, rooms with a gas boiler, oil heater, stove or open fire need a carbon monoxide alarm. Source
- Gas network
- Phoenix Energy runs the natural gas network in its Greater Belfast licence area. Its gas emergency number is 0800 002 001. Source
Smell gas in Northern Ireland?
Call the Northern Ireland gas emergency service on 0800 002 001. This is different from the 0800 111 999 number used in Great Britain. Turn off the gas at the meter if you can, open windows and doors, and don't use electrical switches or flames.
If you smell oil fumes or soot, or a carbon monoxide alarm sounds, turn the boiler off, ventilate the room and get everyone outside.
Things you can check first
On a gas combi, check the pressure gauge. Below about 1 bar, top up using the filling loop, as shown in our boiler pressure guide.
On an oil boiler, check the tank has oil in it and the gauge isn't stuck. If you've just had a delivery after running low, sludge from the bottom of the tank may have blocked the filter, which needs a technician.
Common faults
Gas boilers fail most often on fans, pumps, diverter valves, ignition and pressure sensors. In Belfast's harder water zones, scale on a combi's plate heat exchanger can cause hot water to run hot and cold.
Oil boilers are more likely to lock out from a blocked nozzle, a failing photocell or an air leak in the supply line. A yearly service prevents most of these.
Renters
Private landlords must keep the heating in repair. Report faults in writing. Housing Executive tenants should report repairs through the Housing Executive, and housing association tenants through their association.
Belfast homes and what they need
Victorian and Edwardian red-brick terraces
Older pipework and radiators in terraces often leak slowly, causing pressure loss. Ask for a leak check if you top up regularly.
Suburban semis
Semis on oil often have the boiler in a utility room or outside. External boilers need their casings and seals checked for water getting in.
Apartments in the city centre and riverside
Flats with electric heating need an electrician, not a gas engineer. Check what system you have before booking.
Areas covered
Engineers who cover Belfast work across areas including Ormeau, Stranmillis, Malone, Ballyhackamore, Sydenham, Andersonstown, Newtownabbey, Holywood, Dundonald and Carryduff.
Questions people in Belfast ask
Should I repair or replace an old Belfast boiler?
Repair if the part is available and the boiler is otherwise sound. If the heat exchanger has failed, compare with our new boiler cost guide.