Quickly estimate how much you could save by switching from gas heating to a heat pump
Additional Savings
If you disconnect your gas connection after installing a heat pump, you can make an extra saving on standing charges. This saving not included in the calculator results.
Gas Boiler Efficiency
You can get the theoretical efficiency of a gas boiler from the datasheet. Typically, this will be around 65% for a non-condensing model, and around 87% for a condensing boiler.
However, for condensing boilers, the real-world efficiency is often much lower than what the datasheet says. Unless you’ve got weather compensation enabled, or have finely tuned the water flow temperature, it’s unlikely that your condensing boiler is operating anywhere near its theoretical efficiency.
Heat Pump Efficiency
Real-world heat pump efficiency varies massively. Some examples below:
| Efficiency (%) | SCOP Score | |
| Premium ground source heat pump, with underfloor heating and excellent design and installation | 600% | 6 |
| Good quality air-source heat pump system, designed and fitted by a skilled installer [upper end] | 470% | 4.7 |
| Good quality air-source heat pump system, designed and fitted by a skilled installer [lower end] | 370% | 3.7 |
| *Mediocre design and installation | 300% | 3.0 |
| *Botch-job | 160% | 1.6 |
Also note, if you have a poorly insulated house and use a “blast of heat” each evening, then it will be difficult to achieve a good “SCOP” score, unless you first upgrade the insulation.
See Also
Oil boiler vs Heat Pump Calculator
Further Reading
Detailed Guide to Air-Source Heat Pumps in Ireland
Ground-Source Heat Pumps in Ireland
