Air to water heat pumps in Ireland
An air to water heat pump costs €9,000–€14,000 fully installed in Ireland. It is the type fitted in about 90% of Irish homes, heats both the radiators and the hot water, and qualifies for the full SEAI grant of up to €14,500.
What is an air to water heat pump?
A fan unit outside the house takes heat from the outdoor air and passes it to the water in your heating system. That water runs through the radiators or underfloor pipes and heats the hot water cylinder.
It replaces an oil or gas boiler directly, which is why it suits most Irish homes. It has a COP of 3.0–4.0, meaning 3 to 4 kWh of heat for every 1 kWh of electricity.
Air to water heat pump cost
| Item | Cost | Notes |
|---|---|---|
| Air to water heat pump unit | €4,000–€7,000 | Price depends on the brand and the kW size |
| Installation and labour | €3,000–€5,000 | 2 to 3 days for an air source system |
| Hot water cylinder | €800–€1,500 | Usually replaced, as a heat pump needs a compatible cylinder |
| Radiator upgrades | €1,000–€3,000 | Only if the existing radiators are undersized |
| BER assessments, before and after | €300–€500 | Required for the SEAI grant |
| Total before grant | €9,000–€14,000 | Not every home needs every item |
After the grant, most homes replacing oil or gas pay about €4,000 or less. See the full heat pump cost breakdown.
Air to water heat pump price by house size
| Home | Typical heat pump size | Installed price before grant |
|---|---|---|
| 2-bed terrace or apartment | 5–8 kW | €8,000–€11,000 |
| 3-bed semi-detached | 8–11 kW | €9,000–€13,000 |
| 4-bed detached | 11–14 kW | €11,000–€15,000 |
| 5-bed or larger detached | 14–16 kW | €13,000–€18,000 |
Radiators, cylinder and space
- Radiators: existing radiators often stay, but undersized ones are replaced with larger ones
- Cylinder: the hot water cylinder is usually replaced with one made for a heat pump
- Outdoor unit: needs a clear spot outside with free airflow
- Noise: 40 to 50 dB at 1 metre, about the level of a quiet conversation
How much does an air to water heat pump cost to run?
An air to water heat pump costs €600–€1,000 a year to run in an average 3-bed home, roughly half the cost of oil heating. A well-insulated home with underfloor heating or large radiators sits at the lower end.
Air to water or ground source?
A ground source heat pump is more efficient but costs €14,000–€18,000 and needs garden space for the ground loops. Both get the same grant. For most homes, air to water is the lower-cost choice.