Heat pump or a new gas boiler?

The grant is substantial and the question is a fair one. But the decision is not really about the grant — it is about whether your house can take a heat pump at all, and how much upheaval you are willing to live through. Neither of those is settled by budget.

The grant, properly explained

The headline is up to €12,500. That is real, but it is not one payment and it is worth knowing how it breaks down before you plan around it.

That last line catches people out. A third of the grant does not arrive for a year, and it depends on the system actually running as it should. If you are working out what you can afford up front, the figure to plan around is €8,500, not €12,500.

There is a second condition worth knowing: the €4,000 bonus and the €2,000 heating upgrade apply when you are switching away from fossil fuel or electric storage heating. Coming off a gas boiler does qualify. Replacing an existing heat pump does not, and that case is capped considerably lower.

Grant structure as of February 2026, when it increased substantially. Amounts and conditions do change — confirm the current position on seai.ie before committing to anything.

The threshold that decides it

This is the part that matters more than anything else on this page.

To qualify, your home has to meet SEAI's Heat Loss Indicator threshold — a measure of how fast your house leaks heat. A heat pump only works properly in a house that holds onto it.

The figure is a low one, and the published thresholds have moved more than once. We are deliberately not printing a number here, because the version you find quoted online is as likely to be out of date as not, and this is not something to plan around second-hand. The assessment is what settles it for your house, and it is the only answer that counts.

How to find out where your house stands

• Built before 2007 — you need a technical assessment from an SEAI-registered advisor. There is a €200 grant towards it
• Built 2007 to 2020 — your existing BER should show the heat loss indicator already
• Built 2021 or later — outside the scheme, though such a house would likely pass easily
• You also need a valid MPRN from your electricity bill

Get the assessment before you get quotes. It costs little, most of it is covered by that €200, and it answers the only question that actually decides this.

A lot of older Irish housing — solid wall, limited attic insulation, original windows — does not pass without significant work first. That work is grant-aided separately, and it is often money better spent than the heat pump itself. But it means the real question is frequently "what would it take to get this house ready?" rather than "heat pump or boiler?"

What actually happens in your house

This is the part people think about least beforehand and most afterwards, and it is a genuine difference between the two jobs.

Neither of those is a criticism of heat pumps — it is simply what the work involves, and a well-run heat pump installation is a bigger job by its nature. But it is worth knowing before you start, particularly if you have young children, you work from home, or it is the middle of winter.

If your boiler died this week, the practical reality is that a gas replacement puts your heating back on tomorrow and a heat pump does not.

When a heat pump genuinely wins

Running costs, honestly

A heat pump is efficient in a way a boiler cannot be. It moves heat rather than making it, so it delivers several units of heat for each unit of electricity — where a very good gas boiler delivers slightly less than one unit of heat per unit of gas.

But electricity costs considerably more per unit than gas in Ireland. So the saving depends entirely on the heat pump achieving that multiple in practice, and it only does so in a house that suits it and with a system sized and set up properly.

In a good house, well installed: usually cheaper to run than gas. In a poor house, or badly commissioned, it can cost more than the boiler it replaced — because the system labours, or falls back on immersion heating to make up the shortfall. Those cases are where the unhappy stories come from, and they are nearly always a house problem or an installation problem rather than a heat pump problem.

So what would we actually say?

If your house already passes the assessment, or is close and you were planning insulation work anyway, and you can live with a fortnight of upheaval — a heat pump is well worth investigating properly. Get the technical assessment first.

For most of the houses we are called to, though, the honest answer is a gas replacement. The boiler has failed or is close to it, the house would need thousands spent on insulation before a heat pump would even qualify, and the family needs heat and hot water now rather than in two weeks. There is no grant towards it, but a modern A-rated condensing boiler still cuts your gas use considerably against something fifteen or twenty years old — and it is done in a day.

What we would not do is let anyone spend five figures on a heat pump for a house that cannot carry it. That is the expensive mistake in this whole area, and the assessment avoids it entirely.