Heat Pump Running Costs UK 2026: Real Numbers vs Gas and Oil
Forget the myths. Here are the actual running costs of heat pumps compared to gas, oil, and LPG, based on real OFGEM tariff data and field-proven efficiency ratings.
Last updated: April 2026 - Based on OFGEM Q2 2026 price cap tariffs
Annual Running Cost Comparison
The table below compares the annual heating costs for a typical 3-bedroom semi-detached home with a heat demand of approximately 12,000 kWh per year. All figures are based on OFGEM Q2 2026 price cap tariffs and average market rates.
| Heating System | Fuel Cost (p/kWh) | Efficiency / COP | Effective Cost (p/kWh heat) | Annual Cost |
|---|---|---|---|---|
| Gas boiler (old, 80%) | 6.76p | 80% | 8.45p | £1,014 |
| Gas boiler (new A-rated, 92%) | 6.76p | 92% | 7.35p | £882 |
| Oil boiler (85%) | ~8.5p | 85% | 10.0p | £1,200 |
| LPG boiler (85%) | ~10.5p | 85% | 12.35p | £1,482 |
| Direct electric heating | 24.5p | 100% | 24.5p | £2,940 |
| Air source heat pump | 24.5p | COP 3.2 | 7.66p | £919 |
| Ground source heat pump | 24.5p | COP 3.8 | 6.45p | £774 |
Based on 12,000 kWh annual heat demand (typical 3-bed semi). Electricity 24.5p/kWh, gas 6.76p/kWh (OFGEM Q2 2026 price cap). Oil at 65p/litre (10.31 kWh/litre). LPG at 58p/litre (6.9 kWh/litre). Standing charges excluded as they apply regardless of heating type.
Why Heat Pumps Are Cheaper Despite Expensive Electricity
The most common objection to heat pumps is: "Electricity costs 3.6 times more than gas per kWh, so how can a heat pump be cheaper?" The answer lies in the Coefficient of Performance (COP).
The simple calculation:
Gas boiler: 12,000 kWh heat needed / 0.92 efficiency = 13,043 kWh gas consumed x 6.76p = £882/year
Air source HP: 12,000 kWh heat needed / 3.2 COP = 3,750 kWh electricity consumed x 24.5p = £919/year
Ground source HP: 12,000 kWh heat needed / 3.8 COP = 3,158 kWh electricity consumed x 24.5p = £774/year
A COP of 3.2 means the heat pump produces 3.2 kWh of heat for every 1 kWh of electricity it consumes. It achieves this by extracting free heat from the outdoor air (or ground) and "pumping" it to a higher temperature using a refrigeration cycle. You are not converting electricity directly into heat; you are using electricity to move heat that already exists in the environment.
At current 2026 tariffs, air source heat pumps are roughly on par with a new gas boiler for running costs, while ground source systems are noticeably cheaper. But the real savings come when replacing older, less efficient gas boilers (80% efficiency or lower), oil boilers, LPG systems, or direct electric heating. For more on the full comparison: Heat Pump vs Gas Boiler.
Running Costs by Property Size
Your actual running costs depend heavily on your home's heat demand, which is determined by its size, insulation level, and local climate. Here are estimates for different property types:
| Property | Heat Demand (kWh/yr) | ASHP Cost (COP 3.2) | GSHP Cost (COP 3.8) | Gas Boiler (92%) |
|---|---|---|---|---|
| 2-bed flat/terrace | 8,000 | £613 | £516 | £588 |
| 3-bed semi | 12,000 | £919 | £774 | £882 |
| 4-bed detached | 16,000 | £1,225 | £1,032 | £1,176 |
| 5-bed large detached | 22,000 | £1,684 | £1,418 | £1,617 |
Heat demand estimates assume reasonable insulation. Poorly insulated homes may have 30-50% higher demand.
Factors That Affect Your Running Costs
COP and seasonal efficiency (SCOP)
The COP varies with outdoor temperature. The Seasonal Coefficient of Performance (SCOP) is the average over a full heating season. A well-installed system in the South of England will achieve a higher SCOP than one in Scotland due to milder winters. Typical SCOP values: air source 2.8-3.5, ground source 3.5-4.5.
Insulation quality
Poor insulation means your home loses heat faster, requiring the heat pump to work harder and longer. Investing in insulation before or alongside a heat pump reduces your heat demand and therefore your running costs. According to the Energy Saving Trust, cavity wall insulation can save £300-£400 per year.
Flow temperature settings
Heat pumps are most efficient at low flow temperatures (35-45 degrees). If your system is set to run at higher temperatures (50+) to compensate for undersized radiators, efficiency drops and running costs increase. Proper system design at installation is critical.
Electricity tariff
Using a time-of-use tariff (like Octopus Agile or Intelligent Octopus) can reduce your electricity cost significantly. Running the heat pump during off-peak hours (typically overnight) when electricity is 7-15p/kWh, rather than the standard 24.5p, can cut running costs by 30-50%.
Weather compensation
Modern heat pumps with weather compensation automatically adjust their output based on outdoor temperature. This prevents the system from overworking on mild days, keeping efficiency high. Most quality brands (Mitsubishi, Daikin, Vaillant) include this as standard.
Hot water demand
Heating domestic hot water to 55-60 degrees requires the heat pump to work at higher temperatures, reducing efficiency. A typical household's hot water accounts for 15-25% of total heat demand. Low-flow showerheads and efficient hot water habits help reduce this.
Reduce Costs Further with Smart Tariffs
One of the most effective ways to reduce heat pump running costs is switching to a time-of-use electricity tariff. Heat pumps with a hot water cylinder are ideal for this because you can heat the cylinder overnight when electricity is cheapest, then use the stored hot water during the day.
| Tariff | Off-Peak Rate | ASHP Annual Cost (3-bed) | Saving vs Standard |
|---|---|---|---|
| Standard variable (OFGEM cap) | 24.5p (all day) | £919 | Baseline |
| Economy 7 (off-peak 7hrs) | ~12p | £700 | £219 |
| Octopus Intelligent | ~7p | £550 | £369 |
Estimates assume 60% of heat pump electricity consumption can be shifted to off-peak hours. Actual savings depend on your lifestyle and system setup.
Long-Term Savings: 10-Year and 20-Year View
The real value of a heat pump becomes clear when you look beyond the first year. Heat pump maintenance costs are low (£100-£200/year for an annual service), and the government's decarbonisation plans are expected to make electricity cheaper relative to gas over the coming decade.
Estimated 20-year total cost of ownership (3-bed semi)
Gas Boiler
£23,640
Running + maintenance + 1 replacement at year 15
Air Source HP
£21,380
Running + maintenance (no replacement needed)
Ground Source HP
£18,480
Running + maintenance (no replacement needed)
Assumes 2% annual energy price inflation. Gas boiler replaced once at year 15 (£2,500). Heat pump lifespan 20-25 years.
Switching from Oil or LPG: Where the Biggest Savings Are
If your home is off the gas grid and currently heated by oil or LPG, a heat pump offers the most dramatic savings. Oil and LPG prices are volatile and have been consistently more expensive than mains gas.
Annual savings from switching to an air source heat pump:
- £281 saved per year vs oil boiler
- £563 saved per year vs LPG boiler
- £2,021 saved per year vs direct electric heating
Combined with the £7,500 BUS grant, homeowners replacing oil can expect payback in as little as 3-5 years. For LPG, payback can be even faster due to higher fuel costs.
Maintenance Costs
Heat pumps have lower maintenance costs than gas or oil boilers because they have fewer moving parts and no combustion process. Here is what to budget for:
| System | Annual Service Cost | Average Repair Cost | Lifespan |
|---|---|---|---|
| Air source heat pump | £100 - £200 | £200 - £500 (rare) | 20 - 25 years |
| Ground source heat pump | £100 - £150 | £200 - £400 (very rare) | 25+ years (loop 50-100) |
| Gas boiler | £80 - £120 | £150 - £400 | 12 - 15 years |
| Oil boiler | £100 - £200 | £200 - £600 | 15 - 20 years |
Frequently Asked Questions
How much does it cost to run a heat pump per year in the UK?
Why are heat pumps cheaper to run than gas boilers when electricity is more expensive?
Will heat pump running costs get cheaper in the future?
Do heat pumps use more electricity in winter?
Find Out Your Exact Running Costs
Get a personalised quote showing exactly what a heat pump would cost to install and run in your home. Our MCS-certified installers provide free heat loss calculations and running cost estimates.