“Will a heat pump cost more to run than my gas boiler?” It’s the question that stops most homeowners in their tracks. The answer used to be complicated — but in 2026, with dedicated heat pump electricity tariffs, the numbers are firmly in the heat pump’s favour.
Let’s break it down with real numbers, not vague promises.
The Key Number: COP (Coefficient of Performance)
Before we get to costs, you need to understand one number: COP (Coefficient of Performance).
A heat pump doesn’t generate heat — it moves it from outside to inside. For every 1 kW of electricity it uses, it typically produces 3–4 kW of heat. This ratio is the COP.
- Gas boiler efficiency: 90–95% (you get 0.9–0.95 kW of heat per 1 kW of gas)
- Heat pump COP: 3.0–4.0 (you get 3–4 kW of heat per 1 kW of electricity)
This means a heat pump is roughly 3–4 times more efficient than a gas boiler. The question is whether this efficiency advantage outweighs the higher price of electricity vs gas.
2026 Energy Prices
As of early 2026, typical energy prices are:
| Fuel | Price per kWh |
|---|---|
| Gas (standard tariff) | ~6.5p |
| Electricity (standard tariff) | ~24.5p |
| Electricity (Octopus Cosy) | ~15p average |
| Electricity (EDF Heat Pump Tracker) | ~14–16p average |
| Electricity (E.ON Next Pumped) | ~15p average |
The ratio of electricity to gas is about 3.8:1 on standard tariffs — which means a heat pump with a COP of 3.8 breaks even. Anything above that, and you save money.
With a heat pump tariff, the ratio drops to about 2.3:1 — making heat pumps significantly cheaper to run.
Running Cost Comparison by Property
Here’s what Bristol households actually spend:
3-Bed Semi-Detached (1930s, cavity walls)
Heat demand: ~12,000 kWh/year
| Heating System | Annual Cost |
|---|---|
| Gas boiler (92% efficient) | £845 |
| Heat pump (COP 3.5, standard tariff) | £840 |
| Heat pump (COP 3.5, Octopus Cosy) | £515 |
Saving with heat pump tariff: £330/year
3-Bed Victorian Terrace (solid walls)
Heat demand: ~15,000 kWh/year
| Heating System | Annual Cost |
|---|---|
| Gas boiler (92% efficient) | £1,060 |
| Heat pump (COP 3.2, standard tariff) | £1,150 |
| Heat pump (COP 3.2, Octopus Cosy) | £700 |
Saving with heat pump tariff: £360/year
Note: the lower COP for Victorian homes reflects the higher flow temperatures needed. Even so, a heat pump tariff delivers significant savings.
4-Bed Detached (1930s)
Heat demand: ~18,000 kWh/year
| Heating System | Annual Cost |
|---|---|
| Gas boiler (92% efficient) | £1,270 |
| Heat pump (COP 3.5, standard tariff) | £1,260 |
| Heat pump (COP 3.5, Octopus Cosy) | £770 |
Saving with heat pump tariff: £500/year
Heat Pump Electricity Tariffs Explained
These specialised tariffs are the game-changer. Here’s what’s available in 2026:
Octopus Cosy
- How it works: Lower rates during off-peak hours (overnight, afternoon), slightly higher at peak
- Average effective rate: ~15p/kWh for heating
- Best for: Homes that can pre-heat during off-peak and coast through peak hours
- Smart meter required: Yes
EDF Heat Pump Tracker
- How it works: Wholesale price tracking with a cap, dedicated heat pump meter
- Average effective rate: ~14–16p/kWh
- Best for: Well-insulated homes with consistent heat demand
- Smart meter required: Yes
E.ON Next Pumped
- How it works: Fixed low rate for heat pump electricity
- Average effective rate: ~15p/kWh
- Best for: Simplicity — one predictable rate
- Smart meter required: Yes
Which Should You Choose?
For most Bristol homeowners, Octopus Cosy offers the best combination of savings and flexibility. The off-peak overnight charging aligns perfectly with heat pump operation — your hot water cylinder charges overnight at the cheapest rate, and the house pre-heats before you wake up.
Oil and LPG: Even Bigger Savings
If you’re currently heating with oil or LPG (common in some Bristol outskirts and South Gloucestershire), the savings are even more dramatic:
| Current Fuel | Annual Cost | Heat Pump (Cosy tariff) | Annual Saving |
|---|---|---|---|
| Oil (3-bed) | £1,400–£1,800 | £515 | £885–£1,285 |
| LPG (3-bed) | £1,600–£2,000 | £515 | £1,085–£1,485 |
For oil and LPG users, a heat pump pays for itself remarkably quickly.
Hot Water Costs
Don’t forget hot water — it’s typically 15–20% of your total heating bill.
A heat pump heats your hot water cylinder efficiently, especially when pre-heating overnight on a low tariff. Typical hot water costs:
- Gas boiler: £120–£180/year
- Heat pump (standard): £100–£150/year
- Heat pump (Octopus Cosy): £60–£90/year
Will Electricity Prices Go Up?
This is the big uncertainty. However, several factors suggest the gap between gas and electricity will narrow over time:
- Carbon pricing — gas will become more expensive as carbon taxes increase
- Renewable electricity — more wind and solar drives down wholesale electricity prices
- Gas phase-out — as gas demand falls, network maintenance costs are spread across fewer users
- Government policy — there’s growing support for rebalancing the electricity/gas price ratio
The trend is clearly towards electricity becoming relatively cheaper compared to gas.
The Bottom Line
In 2026, heat pump running costs are:
- Roughly equal to gas on a standard electricity tariff
- 20–40% lower than gas with a heat pump tariff
- 50–70% lower than oil/LPG regardless of tariff
The days of “heat pumps cost more to run” are over — especially for homeowners who take advantage of the dedicated tariffs now available.