Smart Tariffs for Heat Pumps
How time-of-use electricity tariffs work, which types suit an air source heat pump, and what they could mean for your running costs.
A heat pump uses most of a home’s electricity, so when it runs matters as much as how efficient it is. Smart tariffs charge less at quieter times of day. A heat pump can take advantage of that because a house holds its warmth for hours and a hot water cylinder can be heated in advance. This guide explains the main tariff types, how to set a heat pump up to use them, and includes a calculator so you can test the numbers for your home.
Types of smart tariff
All smart tariffs need a smart meter that records half-hourly readings. The coloured strip on each card shows a typical day, from midnight to midnight.
Standard variable or fixed
One price all day, every day. The Ofgem price cap sets the maximum for standard variable tariffs. Simple, but there’s nothing to gain from timing your heating.
Economy 7 / Economy 10
Older tariffs with a cheaper night rate and a dearer day rate. They were designed for storage heaters. A heat pump runs most of the day, so the higher day rate often outweighs the cheap nights.
Fixed cheap windows
Built for heat pumps, with set cheap periods every day, often including an afternoon slot. Some also have a 4–7pm peak that costs more than the standard rate. Others have no peak at all.
Long overnight window
A very cheap 5–7 hour overnight rate for the whole home, but you need an eligible electric car or charger. Worth comparing if you have an EV and a heat pump.
Half-hourly prices
Prices follow the wholesale market and change every half hour, published a day ahead. Overnight and windy, sunny periods can be very cheap, and occasionally prices go below zero. The 4–7pm peak is expensive. Best with automation.
How a heat pump works with a smart tariff
- Your home is a heat store. Heat pumps run best low and slow. Raising the room temperature by a degree or two in a cheap window lets the house coast through the dearer hours that follow. Well-insulated homes and underfloor heating screeds hold heat longest.
- Your cylinder is a thermal battery. Hot water is often 15–25% of a heat pump’s electricity. Scheduling the daily reheat into a cheap window is the easiest saving, with no change to comfort.
- Afternoons are a bonus. Efficiency (COP) rises by roughly 2–3% for every degree warmer it is outside, so a 1–4pm window gets cheaper electricity and more heat per kWh.
- Mind the peak. Some tariffs charge 40p/kWh or more from 4–7pm. Turning the heating down during the peak saves money, but turning it right off can make the house cold and the catch-up costly. A modest setback usually works best.
- Don’t overdo the boost. Pre-heating means running at a higher flow temperature, which lowers efficiency (see flow temperature & efficiency). Small, regular boosts beat one big one.
- Controls do the work. Most heat pump controllers allow time-based setpoints and separate hot water schedules. Some apps and smart controls can follow tariff windows automatically. Keep weather compensation on so the heat pump still runs at the lowest flow temperature it can.
- Batteries and solar change the maths. A home battery can be charged in the cheap window and run the heat pump through the peak. Solar panels can cover daytime running in spring and autumn.
UK heat pump and smart tariffs, November 2026
Times and structures as published by each supplier or reported by comparison sites. Rates depend on your region and change, usually every quarter, so always get a quote for your postcode. OVO’s Heat Pump Plus has closed to new customers. Ofgem’s price cap for 1 October to 31 December 2026 is 26.32p/kWh for electricity, with a 54.83p daily standing charge (averages). VAT has been removed from electricity bills from 1 October 2026 to 31 March 2027.
| Tariff | Cheaper periods | Peak | Who can join | |
|---|---|---|---|---|
| Cosy Octopus Octopus Energy | 04:00–07:00, 13:00–16:00, 22:00–00:00, about 51% below the day rate | 16:00–19:00, about 50% above the day rate | Heat pump, electric boiler or electric radiators | Details |
| Heat Pump Tracker EDF | 04:00–07:00 and 13:00–16:00, 10p/kWh below the standard rate | None | Any heat pump | Details |
| Heat pump tariff British Gas | Half price 00:00–07:00 and 13:00–16:00, paid back as a weekly credit | None | Heat pump; rates by postcode quote | Details |
| Next Pumped E.ON Next | Super off-peak 22:00–06:00; off-peak 06:00–16:00 and 19:00–22:00 | 16:00–19:00 | Heat pump | Details |
| Heat Pump Saver ScottishPower | 14p/kWh 11:00–16:00 every day | None | Heat pump, monthly Direct Debit | Details |
| Intelligent Octopus Go Octopus Energy | 23:30–05:30 for the whole home, plus smart-charging slots | None | Eligible EV or charger | Details |
| Agile Octopus Octopus Energy | Changes every half hour; cheapest overnight and at windy or sunny times | Usually 16:00–19:00 | Smart meter only | Details |
Heat pump running cost calculator
Change the inputs to see an estimated annual cost on each tariff type. Click a tariff to see its daily profile and enter your own rates.
1. Your heat demand
Your annual gas use is on your bill or supplier app. A heat-loss survey or our size calculator gives heat demand directly.
2. Your heat pump
Effective space-heating efficiency: –
3. How you’ll run it
Heat is moved from the most expensive half hours first. The penalty covers the extra losses and lower efficiency from pre-heating. On cold days a short window can’t take all the load, so keep this realistic.
Untick to use a typical timer (05:30 and 17:30).
Gas comparison rates
Defaults are Ofgem price cap averages for October–December 2026.
Estimated annual cost by tariff
Calculating…
Total bill = heat pump + rest of home + electricity standing charge. Click a row to view it below.
Compared with a gas boiler
Heating and hot water only. Your electricity standing charge is paid either way, so it’s left out of this comparison. The gas standing charge is only saved if you cap the gas supply.
Method and assumptions
The day is split into 48 half hours. Space heating follows outdoor temperature, which is coldest before dawn and warmest mid-afternoon. Efficiency rises 2.5% per degree, scaled so the yearly average equals your effective SCOP. Effective SCOP is the 35 °C datasheet figure reduced for higher flow temperatures (45 °C ×0.85, 50 °C ×0.79, 55 °C ×0.73). When shifting is on, the chosen share of heating is taken from the most expensive half hours and added to the cheapest periods, plus the shifting penalty. Dynamic tariffs use an illustrative winter price shape scaled to your average and treat the cheapest six hours as the cheap periods. The rest of the home follows a typical UK household profile. The model uses one representative day, so it doesn’t capture very cold spells, defrosting, seasonal price changes or saving-session rewards. Default tariff rates are indicative examples, not quotes. Enter the rates you are offered for an accurate result.
Rates and tariff details checked 2 November 2026 against supplier pages, Ofgem and comparison sites. Heat Pump Database is independent and isn’t paid by any energy supplier.
Frequently asked questions
Do I need a smart meter for a heat pump tariff?
Yes. Every time-of-use tariff needs a smart meter that sends half-hourly readings to your supplier, otherwise it can’t tell when you used the electricity. Smart meters are free from your supplier.
Does my heat pump need to have been installed by the supplier?
Usually not. Most heat pump tariffs accept any working heat pump, whoever installed it. Some suppliers ask for evidence, such as an MCS certificate or a photo of the unit. EV tariffs are different: they need an eligible car or charger.
Will shifting my heating make my heat pump less efficient?
A little. Pre-heating the house before a peak means running slightly warmer, and every extra degree of flow temperature costs roughly 2–3% of efficiency. A small boost of 1–2 °C is normally well worth it when the cheap rate is half price. Big boosts usually aren’t. The calculator includes this as the “shifting penalty”.
Which tariff is best for a heat pump?
It depends on how much of your use you can move, and when. Tariffs with an afternoon window suit heat pumps because the air is warmest then, so efficiency is highest. Tariffs with a 4–7pm peak reward homes that can coast through the evening. If you can’t shift anything, a flat or discount-window tariff with no peak is the safer choice. Put your own numbers into the calculator above.
Is a smart tariff worth it without a battery?
Often, yes. A house is itself a heat store and a hot water cylinder is a ready-made thermal battery. Scheduling the cylinder reheat into a cheap window alone can save money without any change to comfort. A home battery widens the gap further because it lets the whole house run on the cheap rate.
How often do these rates change?
Most variable smart tariffs move with the Ofgem price cap every three months. Dynamic tariffs change every half hour. The next cap announcement is due on 25 November 2026 for January to March 2027.