Heat pump tariffs compared: which works for your whole household?
The best heat-pump tariff is the one with the lowest realistic cost for your whole household, while keeping the home comfortable. The cheapest advertised off-peak price does not establish which offer wins once the rest of the day, standing charges and other electricity are included.
This guide compares the structure of three published UK options and shows how to calculate your own result. Supplier terms checked 29 October 2026. Obtain a current postcode-specific quote before switching; the worked prices below are invented examples, not supplier quotations.
Heat-pump tariffs compared
Tariff | Published cheaper periods | Main comparison point |
|---|---|---|
Cosy Octopus | 04:00–07:00, 13:00–16:00 and 22:00–00:00 | Three daily rates, including a higher 16:00–19:00 peak; check regional fixed or flexible terms |
British Gas Heat Power | 00:00–07:00 and 13:00–16:00 | Published 50% discount on the tariff's unit rate in those periods, applied as account credit; full standing charge remains |
EDF Heat Pump Tracker | 04:00–07:00 and 13:00–16:00 | Published 10p/kWh discount against its regional standard rate during those periods; check variable pricing and eligibility |
Primary sources: Octopus, British Gas and EDF. These are selected examples, not an exhaustive market ranking. Tariff availability, rates, fees and eligibility may change.
A longer cheap window is not automatically better than a shorter one. The price outside it, actual consumption and standing charge can outweigh the difference. Compare current terms from the same date and for your own region and payment method.
Who can get a heat-pump tariff?
Check the supplier's exact rules. They commonly involve an electricity account, a compatible working smart meter and half-hourly readings; equipment and payment conditions differ. You do not necessarily need a heat pump installed by the same supplier, but do not assume every offer accepts every heating arrangement.
Ask when the new rate actually starts. A supplier switch, meter connection and tariff enrolment can be separate steps. Electricity bought on an interim standard tariff should not be priced retrospectively at the hoped-for cheaper rate in your forecast.
Also check what happens if meter communications fail, whether other benefits stop, and whether there is an exit fee or fixed term. Keep the quote and terms rather than relying on an undated screenshot of a headline offer.
Calculate the whole-house bill
Annual electricity cost = consumption in each rate period multiplied by that rate, plus the annual standing charge and relevant fees, less applicable credits.
Include the heat pump, hot water and other household electricity. If you have an EV or battery, include when it actually charges and any constraints on combining tariffs. If you export solar electricity, check whether your export arrangement is compatible and whether its rate changes.
Do not compare a whole-house smart tariff bill with only the heating portion of a standard tariff bill. Use the same annual demand in the first comparison, then model realistic behaviour changes separately.
Worked example: the cheapest unit rate does not always win
Assume a household uses 6,000kWh annually. Of that, 2,500kWh falls into a cheaper window, 2,500kWh into an ordinary window and 1,000kWh into an expensive window. These invented categories illustrate the calculation rather than any particular supplier's schedule.
Original illustrative tariff | Cheap rate | Ordinary rate | Expensive rate | Standing charge | Annual total |
|---|---|---|---|---|---|
A | 12p | 29p | 45p | 60p/day | £1,694 |
B | 16p | 27p | 27p | 55p/day | £1,545.75 |
Single-rate reference | 25p | 25p | 25p | 55p/day | £1,700.75 |
For A, the units cost £300 + £725 + £450 = £1,475, with £219 in standing charges. B's higher cheapest rate still produces a lower total for this consumption pattern.
The standing charge uses 365 days. None of these prices is a real tariff quotation or prediction. The point is to price every unit at the time it is used rather than choosing from one attractive number.
How much demand can you really shift?
Start with half-hourly consumption data if available. Identify the electricity associated with heating and hot water, but remember that household smart-meter data usually combines all uses. A separate heating meter can help explain demand without necessarily measuring system efficiency.
Make a conservative estimate of what can move. Hot-water heating or EV charging may be more flexible than maintaining a comfortable room on a cold evening. Occupancy, building heat loss and equipment capacity constrain the result.
Calculate a second case in which less demand shifts than hoped. If a tariff only saves money with an ambitious schedule that nobody wants to follow, the paper saving may not materialise.
Should you switch heating off during expensive hours?
Avoid treating a tariff window as a universal instruction to stop heating. What works depends on the building, controls, weather and comfort requirements. A schedule that allows the house to become uncomfortably cold may be unacceptable even if a model prices it cheaply.
Ask the installer how the commissioned system can respond to the tariff. Discuss moderate scheduling or setback where appropriate, while preserving frost protection and required hot-water hygiene functions. Record settings before changes and compare performance over meaningful periods.
Raising stored heat can also change efficiency and heat loss. Electricity bought more cheaply is not automatically useful savings if the strategy requires substantially more of it. Our running-cost guide explains the separate roles of price and efficiency.
Illustrative image. The equipment and layout for a particular home must be assessed as part of its design.
What changes if you have an EV?
A household with substantial overnight charging may find an EV-focused tariff competitive even when the heating needs power during the day. Conversely, a heat-pump tariff with several daytime cheap periods may suit another household better.
Compare the combined annual bill with the same realistic vehicle mileage and heating demand. Check charger, vehicle and smart-control requirements, and whether advertised cheap electricity applies to the whole house or only eligible charging.
Do not count an EV's overnight saving twice: once as part of the household tariff comparison and again as an additional benefit. Keep the before-and-after totals consistent.
What changes with solar panels and a battery?
Solar generation can reduce imported electricity when it overlaps with demand. Winter heating demand and annual solar output do not necessarily align, so an annual kWh balance cannot establish a zero-import heating bill.
If you use generation that could otherwise be exported, include the export income forgone. A battery can shift demand but has capacity limits, losses and capital costs. Check how tariff terms interact with battery charging and export payments.
Run a comparison before adding new equipment and another after it, so you can see which savings belong to the tariff and which require extra spending. An attractive tariff should not be presented as paying for a battery unless the complete calculation supports that claim.
Fixed, flexible and tracker: what are you comparing?
A fixed unit rate does not fix the quantity you consume or necessarily your monthly payment. A variable or tracker offer can change under its terms. Check the contract period, how changes are calculated and the route for leaving.
Do not assume every tariff labelled “tracker” follows the same index. EDF's published heat-pump terms describe a regional standard-rate relationship and quarterly changes. Other trackers may have different mechanics. Read the actual terms rather than applying another product's behaviour to it.
Compare total annual cost with uncertainty clearly shown. If a quoted fixed offer and a variable projection use different assumptions about future prices, explain the difference before interpreting the result.
A switching checklist
Obtain dated regional quotes, including all unit rates and the standing charge.
Check the meter, equipment, payment and data requirements.
Price your current annual demand by the relevant time windows.
Add non-heating demand, EV charging and battery use consistently.
Check export compatibility, credits, fees and lost benefits.
Model a cautious demand-shifting case as well as an optimistic one.
Establish the actual start date and interim tariff.
Save the terms and review the first bills against actual half-hourly use.
Heat-pump tariff FAQs
Do I need a separate electricity supply for the heat pump?
Not necessarily. Many offers price the household's metered electricity by time. Check whether the specific offer uses a different structure or equipment arrangement.
Is a heat-pump tariff always cheaper than a standard tariff?
No. The rates, standing charge and household consumption pattern determine the result. Some customers may also prefer a simpler offer even where a smart tariff could save under particular behaviour.
Can I use a tariff with a heat pump from another manufacturer?
Some suppliers explicitly allow this. Confirm the current conditions for your actual equipment and meter before assuming eligibility.
Why has my Direct Debit not fallen?
Payments may reflect account balance, forecasts or how credits are applied. Compare billed consumption, rates and credits before assuming the tariff is not working.
When should I review the comparison?
After a price or contract change, a major change in consumption, or installation of solar, storage or an EV. Use a full heating season where possible rather than treating a mild month as representative.
Related guides for your next step
To understand schedules and temperatures at handover, use our heat pump controls and settings guide.
If Octopus is on your shortlist, our Octopus heat pump desk-based review sets out the offer and the questions to ask.
Sources and method
The comparison describes the suppliers' linked terms at the checking date. Numerical examples are original calculations using invented rates and consumption. There is no claim that one supplier is universally cheapest, and no saving is guaranteed for a particular household.
Images are AI-generated editorial illustrations.
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