Oil Boiler Replacement
New oil boiler,
properly specified.
Replace an end-of-life oil boiler with a new condensing unit across Belfast, Lisburn, Bangor and the rural NI fringe. Grant, Warmflow and Firebird fitted. OFTEC registered, NIHE Boiler Replacement Scheme approved, fixed price from survey.
When to replace
Six honest signs.
Replacement makes sense when the next repair bill, plus the running-cost gap against a modern condensing unit, outweighs the install. Here's how we judge it at survey.
- 01 Boiler is 12 or more years old and has needed two or more repairs in 24 months.
- 02 Last service flagged a worn heat exchanger or burner approaching end of life.
- 03 Annual oil bill has climbed despite consumption staying flat (efficiency loss).
- 04 Boiler is a pre-2005 non-condensing unit (SAP band F or G, ~78% efficient at best).
- 05 Tank itself is past 20 years old and is being replaced at the same time.
- 06 Firmus or Phoenix Natural Gas has extended mains into the street.
Decision: oil or gas?
The honest comparison.
If Firmus Energy or Phoenix Natural Gas has reached your street, gas conversion typically saves 15-25% on annual running costs against a new condensing oil install. Payback on the conversion premium is usually 5-8 years; on a 15-year asset, the maths almost always favours gas where it's available.
If you're off the gas network and likely to remain off it, a new condensing oil boiler is the right answer. Modern condensing oil runs at 92-95% efficiency, against the 78-82% of pre-2005 non-condensing stock that dominates the older rural inventory.
We survey the gas mains position at the boundary as part of the oil-replacement quote. If gas is viable, you get both quotes, oil and conversion, so you can compare like-for-like before deciding.
Oil to gas conversion service · Oil-to-gas cost guide · Boiler Replacement Scheme NI
Pricing
Fitted prices upfront.
Prices below cover boiler, OFTEC commissioning, removal of the old unit, and Building Control notification. Fixed quote follows a home survey.
- Grant Vortex Pro internal, like-for-like swap
- from £2,250 fitted
- Warmflow Utility internal replacement
- from £2,200 fitted
- Firebird Enviromax HE upgrade
- from £2,550 fitted
- External oil boiler swap including base
- from £2,650 fitted
- Boiler + 1,000L bunded tank package
- from £3,400 fitted
- Oil-to-gas full conversion
- see Oil to Gas Conversion
All prices include VAT. NIHE Boiler Replacement Scheme grant of up to £1,700 may reduce out-of-pocket cost.
Brands fitted
Grant, Warmflow, Firebird, Worcester.
Grant Vortex ProGrant Vortex EcoWarmflow UtilityWarmflow ProfessionalFirebird Enviromax HEFirebird EnvirogreenWorcester Heatslave II
Detailed brand notes on the Grant, Warmflow and Firebird pages. Annual service plans for your new boiler: Oil Boiler Servicing.
Recent work
Recent oil installs and conversions.
Questions
Oil boiler replacement FAQ.
What does a typical oil boiler replacement cost in Belfast?
£2,200-£2,800 fitted for a like-for-like internal swap on a current condensing model (Grant Vortex Pro, Warmflow Utility). £2,650-£3,400 for an external. Add £400-£900 if the oil tank is replaced at the same time. Detailed quotes follow a home survey, not over the phone.
Can I get a grant toward a replacement oil boiler?
Yes. The NIHE Boiler Replacement Scheme pays up to £1,700 toward replacing a 15+ year old boiler with a new condensing unit. Eligibility is income-tested. Full detail on the Boiler Replacement Scheme NI guide.
Should I replace with oil or convert to gas instead?
Depends on whether Firmus Energy or Phoenix Natural Gas has reached your street. If gas is available at the boundary, conversion typically saves 15-25% annually on running costs and stacks up financially over 5-8 years. If you're off-mains and likely to stay off-mains, a modern condensing oil boiler is the right answer.
Do you fit reconditioned or second-hand oil boilers?
No. The network only fits new condensing boilers with manufacturer warranty. A second-hand oil boiler has no warranty, no efficiency rating you can trust, and no insurance comfort. The cost saving is rarely worth the risk on a 15-year asset.
What's involved on the day?
One to two days on site. Decommission the old boiler, drain down primaries, fit the new boiler and burner, replace oil line, fit a magnetic system filter and (where appropriate) a chemical flush, recommission and OFTEC certify. A condensate route is added on internal condensing installs.
Will the new boiler be condensing? What does that mean for me?
Yes. All new oil boilers fitted under Building Regulations are condensing. They recover latent heat from flue gases, run at SAP band A (around 92-95% efficient), and need a condensate discharge to drain. Typical annual oil saving over a non-condensing replacement: 15-25%.
How long does an oil boiler last?
12 to 18 years with annual OFTEC servicing. The single biggest factor is fuel quality and combustion adjustment, both of which the annual service controls. Boilers serviced every year often outlast their second decade; boilers neglected often fail at 8-10.
Where the network fits
Oil boiler installs across NI.
OFTEC engineers on the network fit new oil boilers across Lisburn , Newtownabbey , Bangor , Ballymena and Belfast and the surrounding twenty miles, with particular density in the BT28, BT34 and BT70 rural stock where oil heating dominates.
Ready to replace?
Survey,
fixed quote, fitted.
Send your postcode, current boiler brand and approximate age. We'll come back with a survey slot and quote both oil-replacement and gas conversion side by side if gas is at the boundary.
- OFTEC registered installers, NIHE scheme approved.
- Grant, Warmflow, Firebird the three most-fitted oil brands in NI.
- Oil or gas, both quoted when both are viable.
Your progress 0%
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.