Oil Boiler Repair
Oil boiler locked out?
OFTEC engineer today.
Same-day diagnostic call-out for oil boilers across Belfast, Lisburn and Bangor. OFTEC registered, fixed-quote repair, every major oil brand: Grant, Warmflow, Firebird, Worcester Heatslave and the older Riello-burner stock still common in rural NI.
Common faults
What we see most on oil.
Eight oil-specific faults account for the majority of OFTEC call-outs. If your symptom matches one, the boiler is almost certainly fixable on the first visit.
- 01 Burner lockout, reset button pops out repeatedly.
- 02 No fire-up, no flame, photocell or thermocouple at fault.
- 03 Smoke or soot from the boiler, dirty combustion.
- 04 Oil starvation, air in the supply line after a tank refill.
- 05 Loud rumble or kettling, heat exchanger fouled.
- 06 Boiler runs but doesn't make hot water, diverter or PCB at fault.
- 07 Leaking from the boiler base or pump housing.
- 08 Frozen condensate pipe on a condensing oil boiler.
Pricing
Diagnostic, then fixed quote.
An OFTEC engineer attends, diagnoses, and gives you a fixed price before any work starts. No open-ended hourly meter.
- OFTEC diagnostic call-out + first hour
- from £130
- Common repair (nozzle, photocell, pump)
- £220-£380
- Burner overhaul or replacement
- £420-£680
- Heat exchanger clean and recommission
- £280-£480
- Uneconomic repair? Quote a Vortex or Warmflow replacement
- see Oil Boiler Replacement
All prices include VAT. Repair quote agreed in writing before any parts go on.
Brands repaired
Every major oil brand fitted in NI.
Grant VortexWarmflow UtilityFirebird EnviromaxWorcester HeatslaveRiello (burners)MistralTriancoHRM Wallstar
Detailed brand notes on the Grant, Warmflow and Firebird pages. For an annual service rather than a repair, see Oil Boiler Servicing.
Recent work
Recent oil repair and replacement jobs.
Questions
Oil boiler repair FAQ.
What's the difference between an oil boiler repair and a service?
A service is a planned annual maintenance check, flue gas analysis, nozzle inspection and combustion adjustment, typically £110-£140. A repair is reactive: a boiler that's locked out or won't fire. Both are OFTEC work but the repair includes diagnosis from cold, often with parts replaced.
How quickly can someone get out to an oil boiler in winter?
Same-day or next-working-day across Belfast, Lisburn and Bangor for non-firing boilers in cold weather. Rural BT28 and BT34 can occasionally extend to 48 hours in peak demand, the installer flags this at the booking call.
My oil boiler locked out after I refilled the tank. Normal?
Common after a fuel delivery: the bottom of the tank has been disturbed, sediment has reached the supply line, the photocell or non-return valve gets fouled. A quick visit usually resolves it: clear the line, replace the filter element, re-fire and check combustion. Roughly £140-£180 if no parts are needed.
Do I need an OFTEC engineer or will any plumber do?
Oil boiler repair must be carried out by an OFTEC registered technician (OFT-101 or above) to be insurance-valid and to keep manufacturer warranties live. Every installer on the network is OFTEC registered. A general plumber cannot legally commission an oil boiler.
When is it cheaper to replace than to repair?
Generally: boilers 12+ years old that need a heat exchanger or burner replacement are usually beyond economic repair. Below 8 years old, repair almost always wins. Between 8 and 12 years, the call is made on parts cost vs grant eligibility (Replacement Boiler Scheme NI can pay up to £1,700 toward a new oil boiler).
What oil brands does the network repair?
Grant, Warmflow, Firebird and Worcester Heatslave are the daily four. We also work on older Riello-burner installations, Mistral, Trianco, HRM Wallstar and most of the legacy stock still running in rural NI. Parts availability is best on Grant and Warmflow.
Where the network repairs
Oil boiler repair across NI.
OFTEC engineers on the network cover Lisburn , Newtownabbey , Bangor , Ballymena and Belfast and the surrounding twenty miles, including the BT28, BT34 and BT70 rural stock where oil heating dominates.
Oil boiler not firing?
Diagnosed
the same day.
Tell us the symptom and the boiler brand. An OFTEC engineer comes back the same working day to diagnose and quote.
- OFTEC registered engineers, insurance-valid repairs.
- Grant, Warmflow, Firebird, Worcester Heatslave and more.
- Fixed-price repair agreed before parts go on.
No heat, no hot water right now? Send an emergency request.
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Quote request received.
One of our installers will be in touch the same working day. If you don't hear back by end of day, email hello@plumbersni.com.