Heat Pump vs Oil and Gas Boiler
A heat pump produces 3 to 4 kWh of heat for every 1 kWh of electricity it uses. An oil or gas boiler converts roughly 85% to 90% of its fuel into usable heat, and burns it on site. Since 1 January 2025, SEAI funds heat pump installations only, oil and gas boiler replacements no longer qualify for a grant.
Heat Pump vs Oil and Gas Boiler, Compared
| Attribute | Oil or gas boiler | Heat pump |
|---|---|---|
| Efficiency | 85%–90% combustion efficiency | 3–4 kWh heat per 1 kWh electricity |
| Typical annual running cost | €1,800–€2,500 (oil) | €800–€1,600 |
| SEAI grant for a new install | None since 1 January 2025 | Up to €12,500 |
| On-site emissions | Combustion emissions on site | Zero on-site emissions |
| VAT on installation | Standard rate | 9% |
| Fuel exposure | Oil and gas market price swings | Electricity price, can pair with solar PV |
Running cost ranges depend heavily on tariff, home insulation, and correct system sizing. Savings from switching typically fall between 40% and 70%, wider when replacing an older, less efficient boiler.
Why Homeowners Move Away From Oil and Gas
Ireland’s carbon tax on fossil fuels is legislated to keep rising toward €100 per tonne by 2030 under the Finance Act 2020, adding a predictable, compounding cost to oil and gas heating that a heat pump doesn’t carry. Oil prices also swing with global markets, a heat pump’s running cost tracks the homeowner’s own electricity tariff instead.
SEAI’s grant restructure removed fossil-fuel boiler funding entirely from 1 January 2025. A homeowner replacing a failed oil or gas boiler today gets no grant support for a like-for-like replacement, only for switching to a heat pump.
What Changes in the Home
When Staying on Oil or Gas Makes More Sense, For Now
Not ready yet? Hydrotreated Vegetable Oil (HVO) is a drop-in replacement for heating oil that most modern oil boilers can run on with little or no modification, typically €300 to €500 to convert. It’s a bridging option, not a permanent alternative, HVO doesn’t carry SEAI grant support the way a heat pump does.
Heat Pump vs Boiler Questions
Can I still get a grant for a new oil or gas boiler?
No. Since 1 January 2025, SEAI funds heat pump installations only under this scheme, not fossil-fuel boiler replacements.
How much less does a heat pump cost to run than oil?
Typically 40% to 70% less, depending on tariff, insulation, and correct sizing. A well-insulated home on a good electricity tariff sees the larger saving.
Does a heat pump work with my existing radiators?
Often, but they may need upsizing since a heat pump runs at a lower flow temperature than a boiler. An installer confirms this during survey.
What happens to my old oil tank or gas boiler?
A gas boiler is decommissioned by an RGII-registered installer as part of the job. An oil tank is typically removed or decommissioned separately, an installer can advise on this during survey.
See What Switching Would Cost
An SEAI-registered installer surveys the home and confirms an exact quote, including grant eligibility.
Get your free installation quote →