2026-06-22 · HeatNI
Switching from oil to gas in Northern Ireland: what's involved and is it worth it?
Oil-to-gas conversion in Belfast, Bangor, Newtownards and Holywood—Phoenix Energy connection, boiler replacement costs, cashback offers, and when switching makes financial sense.
Thousands of Northern Ireland homes still run on oil heating — and many of their owners are asking whether switching to natural gas makes sense. The short answer is: for most homes that sit on the Phoenix Energy network, it does. But the decision involves more than just fuel costs, and it's worth understanding the full picture before you commit.
Is natural gas available in your area?
Natural gas in Northern Ireland is distributed by Phoenix Energy, and the network doesn't cover every postcode. Your first step is checking whether your street is connected. Phoenix Energy's website has an availability checker, or you can call them directly. If gas is on your road, connecting is typically straightforward. If it isn't, the conversion option isn't currently on the table — though the network is expanding.
Most of Belfast, Bangor, Lisburn, Newtownards, Holywood, Dundonald, Comber, and Donaghadee are well covered, but coverage drops off in more rural areas.
What does the switch actually involve?
1. Network connection
Phoenix Energy connects your property to the gas main. This involves laying a pipe from the street into your home and installing a meter. Phoenix Energy currently offer free connection to the network for customers switching from oil, which removes what was historically a significant upfront barrier.
2. New gas boiler installation
Your existing oil boiler can't simply be converted — it needs to be replaced with a gas-fired boiler. This is where a Gas Safe registered installer like HeatNI comes in. We remove the old oil boiler, decommission the oil tank (if required), and install a new high-efficiency gas condensing boiler in its place.
3. Pipework adjustments
In most NI homes, the existing radiator and pipework circuit can be reused with a new gas boiler, though older microbore pipework sometimes needs partial upgrading. We check this during the survey — it's one of the reasons we don't quote without seeing the property first.
4. Oil tank decommissioning
Once you're switched to gas, the oil tank needs to be properly decommissioned and usually removed. This is typically done by a specialist. We can advise on this as part of the overall project.
What does it cost?
The cost of switching depends on your home, the boiler you choose, and how much pipework needs attention. As a broad guide:
| Cost component | Typical range |
|---|---|
| Gas boiler supply and installation | £1,800 – £3,200 |
| Phoenix Energy network connection | Free (current offer for oil switchers) |
| Phoenix Energy boiler replacement allowance | Up to £600 cashback |
| Oil tank decommissioning / removal | £150 – £400 (if required) |
| Pipework adjustments (if needed) | £200 – £600 |
Phoenix Energy's Boiler Replacement Allowance currently offers £600 cashback and free network connection when you switch from oil to gas — which meaningfully reduces the net cost of the project. Terms apply; check phoenixenergyni.com for current offer details.
Is it worth it financially?
Gas tends to be cheaper per unit of heat than oil, and modern condensing gas boilers run at over 90% efficiency. Most oil-to-gas switchers see lower annual energy bills, though the exact saving depends on your current oil usage, the efficiency of your old boiler, and how gas prices move.
The general view among heating engineers in NI is that homes switching from an older (pre-2010) oil boiler to a new A-rated gas boiler can expect meaningful savings on running costs, with the installation typically paying back over several years. We're honest that it isn't the right call for every property — which is why we go through the numbers with you before you commit.
What are the practical benefits beyond cost?
- Instant heat on demand — gas boilers respond faster than oil systems
- No oil tank on your property — frees up space, removes the risk of oil theft or leaks
- No need to manage oil deliveries or worry about running out
- Gas boiler warranties of 8–12 years from major brands
- Potential to add a smart thermostat easily
What to do next
If you're in Belfast, Bangor, Lisburn, Newtownards, Holywood, Dundonald, Comber, or Donaghadee and want to understand whether switching from oil to gas makes sense for your home, book a callback with HeatNI. We'll carry out a survey, walk through the costs honestly, and coordinate with Phoenix Energy on the connection side.
Phoenix Energy's offers and eligibility criteria may change. Always verify current terms at phoenixenergyni.com before proceeding. Prices quoted are indicative for 2026 and will vary based on property specifics and chosen boiler model.