Oil to gas conversion in Northern Ireland

Who supplies gas where

Natural gas reaches a growing part of Northern Ireland, but not all of it. Three companies run the gas networks:

• Phoenix covers Greater Belfast and East Down, including towns such as Larne, Whitehead and Carrickfergus.
• firmus energy covers a network of towns across the north and south of the province, including Derry~Londonderry, Ballymena and Newry.
• SGN Natural Gas covers the newer west network, including Omagh, Enniskillen, Dungannon, Cookstown and Strabane.

Even inside a gas town, not every street has a main. Rural homes, which are the most likely to be on oil, are often out of reach.

Step 1: check if gas is available

Start with the network operator for your area. Each one can tell you whether there is a main near your property and whether a connection is possible. Have your address and postcode ready.

If gas is available, ask:

• how far the main is from your property boundary;
• whether a connection would be free or what it would cost;
• how long a connection takes from request to meter;
• whether any current offers apply.

Step 2: understand what a conversion involves

Converting from oil to gas is more than swapping one boiler for another. It typically includes:

1. The gas connection: the network lays a service pipe from the main to your property and fits a meter. This is the network’s job, not the heating installer’s.
2. A new gas boiler: installed by a Gas Safe registered engineer, who will size it for your home and fit a flue suitable for gas.
3. Gas pipework: from the meter to the boiler, and to a hob or fire if you want them.
4. Controls: a good conversion is the time to upgrade to modern controls, such as a programmable room thermostat and thermostatic radiator valves.
5. System clean: an older oil system will often have sludge, which a new boiler should not inherit. A chemical clean or power flush, inhibitor and a magnetic filter are normal on a good installation.
6. Oil tank decommissioning: see below.

Ask any installer for a written, itemised quote that covers all of these, so you can compare like for like.

Current offers from the gas networks

Gas networks sometimes run offers to help oil households switch. These change often, so treat anything here as a starting point, not a promise.

Phoenix

• Free connection: Phoenix has offered free connections to eligible homes, covering up to 50 metres of service pipe where the gas main is within 50 metres of the property’s front boundary. The 2025 terms said the offer could be withdrawn or amended at any time.
• Boiler Replacement Allowance: in 2026, Phoenix ran a £600 cashback for owner-occupiers switching from oil, LPG, Economy 7 or solid fuel, with household income under £90,000. It applied to connection requests made between 1 June and 30 October 2026, and required an A-rated condensing gas boiler from a list of named manufacturers.

Check the current offers on Phoenix Energy’s website before you plan around either.

firmus energy and SGN

To confirm: verify current firmus energy and SGN Natural Gas connection offers and terms for oil to gas conversions

Is converting worth it?

There is no single answer, and anyone who gives you one without seeing your house is guessing. The things that matter:

The state of your oil boiler

If your oil boiler is fairly new, efficient and well serviced, converting purely to save money may take many years to pay back. If it is old, inefficient or failing, you are buying a new boiler anyway, and comparing a new oil boiler with a gas conversion makes sense.

A service with a combustion test tells you how efficiently your oil boiler is running today. That is a good starting point. See should you replace a 20-year-old boiler?.

Fuel prices

Oil and gas prices move separately. Oil can be cheaper than gas in some months and dearer in others. Gas is paid as you use it; oil is bought in bulk, which some households prefer and others find hard to budget for.

Convenience

Gas means no tank, no running out, no oil deliveries and no risk of oil theft or leaks. For many people that is the main reason to switch.

Distance to the main

If a connection is free, the sums are simpler. If it is not, the cost of laying a service pipe can change the picture.

What happens to the oil tank

When you stop using oil, the tank should not just be left. It should be:

• emptied, ideally by running the oil down before the switch or having it pumped out;
• cleaned of sludge and residue;
• removed, or cut and made safe if removal is not practical.

This should be done by a competent firm that disposes of the oil and waste properly. A redundant tank that still contains oil can leak and cause pollution, and the clean-up is the owner’s responsibility.

After the conversion

A new gas boiler still needs a service every year by a Gas Safe registered engineer, both for safety and to keep the manufacturer’s guarantee valid. Check your guarantee terms, register the boiler with the manufacturer if required, and keep every service record.

How we can help

To confirm: confirm whether Blueprint offers boiler installation or oil to gas conversions; if not, keep this section to servicing only

Whatever you decide, we service both fuels. If you are still on oil, an oil service at £89 with a CD/11 record will tell you how your current boiler is doing. Once you are on gas, a gas service is £79. Book online or email [email protected].