Northern Ireland is the most oil-dependent housing stock in the UK, so oil boiler grants get searched hard here. The honest position in 2026 is narrower than most pages admit.
The Boiler Replacement Scheme, which used to be the main route for oil boiler replacement, closed on 21 September 2023. What remains is the Affordable Warmth Scheme for lower-income households, NISEP through energy suppliers, and Phoenix connection offers if you are switching to gas.
Here is what each covers, who qualifies, and the order to check them in.
The live schemes for oil homeowners
1. Affordable Warmth Scheme (the main one)
- Income: gross household income under £23,000 a year
- Disregarded: PIP, DLA, Attendance Allowance and Carer’s Allowance do not count as income
- Covers: heating measures including boiler replacement, alongside insulation, on a surveyed priority order
- Applies to: owner-occupiers and some private tenants
- Route in: your local council’s Affordable Warmth team, or the Housing Executive
- Contractor: appointed by the scheme, not chosen by you
Full details: Affordable Warmth Scheme NI.
2. NI Sustainable Energy Programme (NISEP)
- Run through: energy suppliers (Power NI, SSE Airtricity, Budget Energy, Click Energy)
- Income tested: low-income households, benefits, fuel poverty
- Covers: boiler replacement, insulation, oil-to-gas conversion
- Grant amount: variable, sometimes up to 100% of cost for qualifying households
- Apply: through your energy supplier directly
Which to choose
The honest comparison:
| Your situation | Best route |
|---|---|
| Household income under £23,000, oil boiler any age | Affordable Warmth, via your council |
| On PIP, DLA, Attendance Allowance or Carer’s Allowance | Affordable Warmth, and check again: those payments are disregarded as income |
| Low-income, switching oil-to-gas | Affordable Warmth or NISEP, plus a PNG connection offer |
| Household income £23,000 to £40,000 | No boiler grant currently applies |
| Higher income, any boiler age | No grant. Work from real prices instead |
Affordable Warmth and NISEP are alternative routes, not stackable pots: both will ask whether you have applied to the other. Phoenix connection offers sit on the gas supply side rather than the boiler side, so they can run alongside (Phoenix Natural Gas grants).
The £23,000 to £40,000 gap is real. The old Boiler Replacement Scheme covered that band and nothing has replaced it. If that is you, no amount of searching will turn up a scheme, and the Warm Healthy Homes Fund consultation (closing 19 August 2026) is where that gap is currently being decided: Warm Healthy Homes Fund NI.
Oil-to-oil replacement costs
If no grant applies, these are the real numbers to plan against.
Typical Belfast oil-to-oil replacement cost:
| Item | Typical range |
|---|---|
| New condensing oil boiler (Grant, Warmflow, Firebird) fitted | £2,400-£3,800 |
| Oil line renewal | £120-£220 |
| Tank gauge and filter renewal | £85-£140 |
| Minor system flush | £180-£280 |
| Commissioning + OFTEC cert | included |
| Gross total | £2,800-£4,400 |
If you qualify for Affordable Warmth, the scheme’s appointed contractor carries out the work and you are not quoting it on the open market at all. These figures are for households paying privately, which is now most of them.
See Oil Boiler Servicing for current-boiler care before replacement becomes urgent.
Oil-to-gas switch: the bigger picture
Many homeowners weigh a switch to gas rather than an oil-to-oil replacement. The maths, paying privately:
| Route | Gross cost | Annual running cost saving |
|---|---|---|
| Oil-to-oil replacement | £2,800-£4,400 | £100-£250 |
| Oil-to-gas conversion | £4,500-£8,500 | £450-£900 |
A Phoenix connection offer, where one is running and your address is in network, comes off the conversion figure. Payback on the extra conversion cost is usually 4-7 years. Full maths: Oil to gas conversion cost NI.
Reasons to stay on oil: outside the PNG network, large heat load with bulk oil contract, listed property with flue restrictions.
Reasons to switch: in-network, oil boiler 12+ years old, staying 5+ years.
Application order
- Check the Affordable Warmth income test. Under £23,000 gross, with disability benefits disregarded. Contact your local council’s Affordable Warmth team.
- Check your electricity supplier for a current NISEP offer.
- If switching to gas: check PNG network coverage at your address.
- If nothing applies, price the work privately rather than waiting on a scheme that will not come.
Free impartial help deciding: NI Energy Advice Line, 0800 111 44 55.
What we do
We are an introducer service. We connect you with independent OFTEC registered engineers for oil work and Gas Safe registered engineers for gas work. The engineer quotes you directly, holds the contract, carries out the work and issues the certification and warranty registration.
We are not a grant administrator, we cannot submit or influence an application, and if you qualify for Affordable Warmth the scheme appoints its own contractor rather than us.
Areas covered: Belfast, Lisburn, Newtownabbey, Bangor, Ballymena, Carrickfergus, Newtownards, Downpatrick and surrounding. See Areas we cover.
Get a quote
Send us:
- Current oil boiler make and age
- Postcode
- Whether you are waiting on an Affordable Warmth referral, so we can tell you whether a private quote is worth having yet
Related services: Oil to Gas Conversion · Oil Boiler Servicing · Oil Boiler Replacement
Related guides: Affordable Warmth Scheme NI · Boiler Grants Northern Ireland · Boiler Replacement Scheme NI · Oil to gas conversion cost NI