New boiler cost in Belfast & Northern Ireland (2026 prices)

"How much will a new boiler cost?" is the question we're asked most often before a survey. The honest answer is: it depends — but there's a realistic range for Northern Ireland homes, and the factors that push costs up or down are fairly predictable.

The short answer: what to budget

For a like-for-like combi boiler replacement in a typical Northern Ireland home — existing pipework in decent condition, accessible flue route, straightforward location — you're looking at roughly £1,800 to £2,800 all-in for supply and installation from a reputable company.

That's not a definitive quote. But it's the range where most standard jobs in Belfast, Bangor, Lisburn, and North Down land when the survey confirms there are no complications.

Job type	Typical NI range
Combi replacement (like-for-like)	£1,800–£2,800
System boiler replacement	£2,000–£3,200
Back-boiler removal + combi install	£2,500–£4,000
Oil boiler replacement	£2,200–£3,500
Oil-to-gas conversion	£3,500–£6,000+

These figures include boiler, labour, flue, magnetic filter, chemical flush, controls, and certification — as they should. If a quote is significantly cheaper and doesn't mention some of these items, ask what's been left out.

What drives the price of a new boiler install

The boiler itself — Output rating (kW), brand, and model account for roughly £600–£1,400 of the total. Worcester Bosch and Ideal are the most common installs in NI; Vaillant and Viessmann sit at a slight premium but carry longer warranties.

Pipework condition and changes — Older NI homes, particularly pre-1990s terraces in south Belfast and central Bangor, often have microbore pipework that needs partial upgrading for a new boiler to run efficiently. This is where surprises happen — which is why a survey matters.

Flue route — A straightforward horizontal run through an external wall costs less than a vertical flue through a roof, or a run that needs to navigate period stonework or awkward bends.

Removal and disposal — Removing a back-boiler (common in older Belfast and Holywood properties) adds time and cost. Properly disposing of the old unit is included in most professional quotes; check if it's not explicit.

Controls and thermostat — A basic wired room stat costs much less than a Hive or Nest smart thermostat. Neither is wrong — it depends on what you want. Smart controls are worth adding when an engineer is already on site; retrofitting later costs more in labour.

Magnetic filter and system flush — Any reputable installer will include a Magna Clean or equivalent filter and a chemical system flush as standard. These protect the new boiler from the sludge that damaged the old one. If a quote doesn't mention either, it's a red flag.

Which brands do Belfast and NI installers recommend?

Worcester Bosch — The most-installed brand in the UK. Strong reliability record, plentiful spare parts, excellent warranty (8–12 years when installed by an accredited installer). The Greenstar 4000 and 8000 Life are widely fitted across NI.

Ideal Heating — Built in Hull, popular in NI for competitive pricing and performance in tight spaces. Logic+ and Vogue ranges are fitted across countless Belfast and Bangor airing cupboards. 10-year warranty when registered.

Vaillant — German engineering, quieter operation, slightly premium feel. ecoTEC is the workhorse range; ecoFIT is a strong value option. Warranties of 7–10 years.

Viessmann — Premium efficiency on the Vitodens 100/200 ranges. Pricier upfront, but exceptional build quality and often the right fit for larger Holywood or Cultra properties with higher heating demand.

Do I need a survey before getting a quote?

Yes — and any company that gives you a firm price without seeing the property is working from assumptions, not facts. Flue routes, pipework condition, gas pipe sizing, access, and the specific install environment all affect the real cost.

A phone call or photos can help start the conversation, but they don't replace a site visit. We survey before quoting — it's the only way to give you a price that will actually hold.

Booking a new boiler survey with HeatNI

If you're ready to get quotes for a replacement boiler in Belfast, Bangor, Lisburn, Newtownards, Holywood, Dundonald, Comber, or Donaghadee — book a callback with your postcode, current boiler details, and an idea of your timescales. We'll arrange a survey and talk through options honestly before you commit to anything.

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Prices are indicative for 2026 and will vary based on property specifics, chosen boiler model, and any additional work required. Always confirm the full scope in writing before proceeding.