This guide explains how to use storage heaters in a UK home on an Economy 7 or similar off-peak tariff: what the input and output dials do, which settings to start with in each season, how to avoid paying peak rates, and how to check whether the tariff is actually saving you money. If you have just moved into a flat or house with storage heaters, learning how to use storage heaters properly is the quickest way to stay warm without a shock bill.
Quick answer: To learn how to use storage heaters, remember two dials. Input sets how much heat is stored overnight on cheap electricity; output sets how fast it is released next day. Raise input in cold weather, keep output at minimum overnight and when out, turn it up in the evening, and avoid the boost button, which uses peak-rate power.
How do storage heaters work?
A storage heater uses off-peak electricity overnight to heat a core of dense bricks inside an insulated case, then gives that heat off during the following day. Dimplex’s operating instructions describe exactly this: the core is charged during the off-peak period and the stored heat is released gradually through the day, with a damper letting room air through the hot core when more heat is needed.
Anyone working out how to use storage heaters should start with the tariff, because the heaters only save money with a cheaper night rate, such as Economy 7. Council guidance, for example the Folkestone and Hythe District Council storage heater factsheet, says charging normally runs from about midnight to 7am in winter and about 1am to 5am in summer, but the exact hours depend on your meter and supplier. Check your bill or ask your supplier for your own off-peak window, and see our guide to Economy 7 hours.
What do the input and output settings do?
The input dial controls how much heat the heater stores during the off-peak period, and the output dial controls how quickly that stored heat is let out into the room. Getting how to use storage heaters right is mostly about setting these two dials for tomorrow’s weather and your routine.
| Control | Other names | What it does | When it uses electricity |
|---|---|---|---|
| Input | Charge, heat store | Sets how much heat is stored overnight. On some models it sets a target room temperature for the end of the charge. | Off-peak only |
| Output | Boost, room temperature, damper | Opens a flap so room air passes through the hot core and takes heat out faster. | Uses no electricity itself; it releases heat already stored |
| Convector or boost heater (some models) | Booster, top-up | A separate heating element that gives instant heat. | Any time, at the peak rate |
Dimplex’s instructions for its XLS series, for example, advise starting the input knob at the midway position, adjusting it after the first day for comfort, and keeping the output knob at minimum in a home, turning it up only for an evening boost and returning it to minimum before bed.
What settings should you use in each season?
Knowing how to use storage heaters through the year starts with a low to medium input in autumn and spring, raise it in winter, and switch the heaters off at the wall in summer if you need no heat. The table gives starting points drawn from manufacturer and housing provider guidance, on a typical 1 to 6 dial; your heater’s scale may differ, so treat them as a first guess and adjust by one step at a time.
| Season | Input (charge) | Output during the day | Output overnight and when out |
|---|---|---|---|
| Autumn | 1 to 3, rising as it gets colder | Low, raise in the evening | Minimum |
| Winter | 4 to 6; maximum in very cold spells | Low in the morning, higher from late afternoon | Minimum |
| Spring | Back down to 1 to 3 | Low, raise in the evening | Minimum |
| Summer | Off at the wall, or a low setting only if needed | Off | Off |
The logic is simple: input is a decision about tomorrow made tonight, and output is how you spend what you have stored. If the heater is cold by early evening, raise the input one step. If rooms are too warm in the morning, lower it one step or check that the output is not left high overnight.
How to use storage heaters day to day
The day to day routine for how to use storage heaters is to set the input each evening for the next day’s weather and move the output dial to match when you are home. These steps work for most manual heaters:
- Check the forecast in the evening. If tomorrow is colder, raise the input one step; if it is milder, lower it one step.
- Before bed, turn the output to minimum so heat is not wasted while you sleep.
- In the morning, leave the output low if the room is comfortable, or raise it a little for an hour while you get ready.
- If you go out for the day, set the output to minimum to keep the heat in the core.
- From late afternoon, when the stored heat is most needed, turn the output up gradually.
- Avoid the boost or convector button and plug-in heaters; if you keep running short, raise the input instead.
- Keep doors to heated rooms closed and draw curtains at dusk, keeping them clear of the heater.
Automatic and high heat retention heaters adjust their charge from a built-in thermostat and timer. On those, follow the manufacturer’s manual, because the dials may set a room temperature rather than a charge level.
How much does a storage heater cost to run?
Part of knowing how to use storage heaters is knowing what each charge costs. A storage heater uses its element rating multiplied by the hours it charges, priced at your off-peak unit rate: a 2.55 kW heater charging for 7 hours can use up to 17.85 kWh a night. The real figure is often lower, because the input setting and the heater’s own controls cut the charge on milder nights.
| Example heater rating | Maximum charge in 7 hours | Cost at an example 14p night rate | Same energy at an example 30p day rate |
|---|---|---|---|
| 1.7 kW | 11.9 kWh | £1.67 | £3.57 |
| 2.55 kW | 17.85 kWh | £2.50 | £5.36 |
| 3.4 kW | 23.8 kWh | £3.33 | £7.14 |
The 14p and 30p figures are example values only, not current tariffs; Economy 7 rates vary by supplier and region, so replace them with the rates on your bill. The storage heater running cost calculator does this with your own rating, hours and rates, and the electric heater running cost calculator compares a plug-in heater used at the day rate.
Is Economy 7 actually saving you money?
Economy 7 only pays if enough of your electricity is used at night, because the day rate on these tariffs is usually higher than a single-rate tariff. Ofgem’s 2026 decision on typical consumption uses 3,400 kWh a year for a typical multi-rate household and assumes 58% of it is used at the peak rate and only 42% off-peak.
You can work out your own break-even share. Divide the difference between your day rate and the single rate by the difference between your day rate and night rate. Example: with an example day rate of 30p, night rate of 14p and the October 2026 cap single rate of 26.32p, (30 − 26.32) ÷ (30 − 14) = 0.23. In that example you need more than 23% of your electricity at night to beat the single rate, and storage heaters charging overnight usually push you well past that.
The Economy 7 calculator runs this check with your own meter readings. Moving other loads such as the washing machine, dishwasher and immersion heater into the off-peak window helps further; our guide to the best time to use electricity in the UK covers how. Households with a home battery can also charge it overnight; the home battery savings calculator estimates that saving.
How to use storage heaters safely
Never cover a storage heater or block its grilles, keep curtains and furniture away from it, and fit a guard where young children or vulnerable people could touch it. Dimplex’s instructions say to keep curtains at least 75 mm from the top and ends, not to sit or stand on the heater, and to supervise children.
- The surface, especially the air outlet grille, gets hot during use.
- Do not dry clothes on or over the heater.
- Storage heaters are very heavy and must be fixed securely to a sound wall; do not move one yourself.
- When first switched on, a new heater may smell for a few days; ventilate the room.
- Storage heaters are usually wired on dedicated off-peak circuits. Any repair, replacement or new circuit must be carried out by a qualified electrician to BS 7671, and in England and Wales Part P of the Building Regulations applies.
If your heaters are old, controls are faulty or the home is still cold with the input on maximum, ask your landlord or a qualified electrician to check them. Our guide to the cheapest way to heat a house in the UK compares storage heaters with other options.
Frequently Asked Questions
Should I leave my storage heaters on all the time?
Leave the wall switch on through the heating season so the heaters can charge each night, but adjust the input to the weather. Turn the output to minimum overnight and when you are out. In summer, if you need no heat, switch them off at the wall.
Why are my storage heaters cold in the evening?
The stored heat has usually run out because the input is too low or the output was left high during the day. Raise the input one step for the next night and keep the output at minimum until late afternoon, then turn it up.
Should I use the boost button on a storage heater?
Only when you really need instant heat. The boost or convector element runs on electricity at the time you press it, usually the expensive day rate. Raising the input setting the night before is normally much cheaper than boosting.
What number should my storage heater be on?
As a starting point on a 1 to 6 dial, use input 1 to 3 in autumn and spring and 4 to 6 in winter, with output at minimum overnight. Adjust by one step at a time over a few days until rooms are warm enough in the evening.
Do storage heaters work without Economy 7?
They will heat the home, but they will charge at the single rate, which removes the main reason for using them. Storage heaters are designed for a tariff with a cheaper night rate such as Economy 7. Check your bill shows two rates.
Checked October 2026 by the Solaxyra Editorial Team. Sources: Dimplex XLS storage heater operating instructions, Folkestone and Hythe District Council: how to use electric storage heaters, Ofgem: typical domestic consumption values decision, Ofgem: energy price cap 1 October to 31 December 2026.