Are Storage Heaters Expensive to Run?

Annual running costs on Economy 7 compared with gas and other electric heating, and what actually drives the bill.

Last reviewed: 2026-06-27 • Reading time: 7 minutes • Verified against: 5 sources

Storage heaters on Economy 7 cost £900–£1,400 a year to run in a typical 3-bedroom home, against roughly £720 for gas central heating. They cost less than electric panel heaters on a standard tariff (£1,500–£2,200/year) because most of their electricity is bought off-peak at around 9p/kWh instead of the standard 24p/kWh rate. Whether you land near the top or bottom of that range depends heavily on the age of the heaters, how well the house is insulated, and how disciplined you are about the input dial.

Annual Running Costs (2026 UK Rates)

Heating System	Annual Cost (3-bed)	Tariff
Storage heaters (modern)	£900–£1,200	Economy 7 (9p off-peak, 28p peak)
Storage heaters (old)	£1,200–£1,400	Economy 7 (poor heat retention wastes charge)
Electric panel heaters	£1,500–£2,200	Standard rate (24p/kWh)
Gas central heating	£720	Gas (6p/kWh)

What Actually Drives Your Storage Heater Bill

Two houses with identical storage heaters can end up with running costs a few hundred pounds apart. The heater is only one part of the equation. What matters most:

Insulation standard. A poorly insulated Victorian terrace with single glazing and no loft insulation can need double the heat input of a well-insulated 1990s semi of the same floor area.
Number and size of heaters. Undersized heaters in cold rooms often get topped up on the expensive peak rate because the overnight charge runs out by mid-afternoon.
How you set the input dial. Charging to maximum every night regardless of weather wastes money on mild days. Charging too little means running out of heat and reaching for a plug-in heater on peak rate.
Occupancy pattern. A house occupied all day needs more stored heat released steadily than one that's empty from 8am to 6pm.
Hot water. If your immersion heater or hot water cylinder also runs off the Economy 7 circuit, that adds to the bill but isn't really a "heating" cost.

Why Storage Heaters Cost More Than Gas

Even at the cheaper Economy 7 off-peak rate (around 9p/kWh), electricity is roughly 1.5 times more expensive than mains gas (around 6p/kWh) per kWh of heat delivered, once you allow for a typical gas boiler's efficiency losses.

For a 3-bedroom home using around 12,000 kWh a year of heat:

Storage heaters (roughly 80% charged off-peak): 9,600 kWh × 9p + 2,400 kWh × 28p = £864 + £672 ≈ £1,100/year
Gas central heating (around 90% boiler efficiency): about 13,300 kWh of gas × 6p ≈ £800, which nets down to roughly £720/year once standing charges and typical billing are factored in

That gap of £180 to £680 a year, depending on the model and how well the tariff is managed, is the real-world price of not having a gas connection. It isn't as steep as running panel heaters on the standard rate, but it's still a meaningful premium over gas.

Running Costs by Property Type

Heat demand scales roughly with floor area and exposed wall surface, so smaller, better-insulated properties cost less to heat than larger or older ones. These are broad ranges, not quotes, since insulation standard varies enormously within each category:

1-bed flat (well insulated): £450–£700/year
2-bed terrace: £700–£1,000/year
3-bed semi: £900–£1,400/year
4-bed detached: £1,300–£1,900/year

Flats tend to sit at the cheaper end even accounting for size, because they usually have fewer exposed walls and benefit from heat shared with neighbouring units. Detached houses lose heat from all four sides and the roof, which is why they need noticeably more storage capacity to stay comfortable through the day.

Economy 7 vs Economy 10

Economy 7 gives you roughly seven hours of cheap overnight electricity, usually somewhere in the 00:30–07:30 window depending on supplier. Economy 10 tariffs, less common now but still offered by some suppliers, spread ten cheaper hours across the day: a few hours overnight, a block in the early afternoon, and a short evening window.

For storage heaters specifically, Economy 7 is usually the better fit because storage heaters are designed to charge in one long overnight block and release heat through the day. Economy 10 suits homes with underfloor heating or hot water systems that can use the extra daytime cheap-rate windows. The off-peak rate on Economy 10 isn't always identical to Economy 7, so it's worth comparing actual unit rates from your supplier rather than assuming one is automatically cheaper.

Reducing Storage Heater Running Costs

Replace old storage heaters. Modern high-heat-retention models have thicker insulation around the ceramic core, so less heat escapes before you need it. Swapping a 20-year-old heater for a modern equivalent typically cuts that heater's running cost by £150–£300 a year.

Match the input dial to the forecast. Charging to maximum every night regardless of weather is the single biggest cause of wasted spend. On mild nights, a lower input setting still leaves enough stored heat for the day.

Avoid topping up on peak rate. If a heater runs cold by mid-afternoon, it's usually undersized for the room or set too low overnight, not something to fix by switching on a plug-in heater at 28p/kWh.

Shift other appliances to off-peak hours. Washing machines, dishwashers, tumble dryers and EV charging all cost roughly a third of the standard rate if run inside the Economy 7 window. This doesn't reduce the heating bill directly, but it lowers your overall electricity spend and makes the tariff worth having.

Improve the building fabric. Loft insulation, draught-proofing and cavity wall insulation (where the property has cavity walls) reduce heat demand across the board, which means smaller overnight charges and lower bills regardless of which heaters you own.

Consider smart storage heaters. Wi-Fi-connected models can adjust the charge automatically based on a weather forecast rather than a manual guess, and let you check remotely whether a heater has run cold. They cost more upfront (typically £400–£700 per heater) but reduce the guesswork that causes most wasted spend.

When Storage Heaters Make Financial Sense

You have no gas connection, and running a new gas main to the property would cost £1,000 or more
You're already on Economy 7 for another reason, such as an immersion cylinder, EV charging or a heat pump
Upfront cost matters more than running cost (storage heaters typically £1,800–£3,000 whole house vs £4,000–£6,000 for a new gas boiler and radiators)
You already have modern high-retention storage heaters, which keep running costs at the lower end of the range

Common Myths About Storage Heater Costs

"Storage heaters are always expensive." Not necessarily. The gap between a well-managed modern setup and a neglected old one is often £300–£500 a year, which is a bigger swing than the difference between storage heaters and gas in many cases.

"You can't control them, so you can't save money." Older heaters do have limited control, but modern models with thermostats and fan-assisted output give you far more say over when heat is released, which reduces waste from overheating empty rooms.

"Switching off a storage heater at the wall saves money." If the heater has already charged overnight, switching it off doesn't return that electricity, it just stops the room getting the heat you've already paid for. The saving comes from reducing the input setting the night before, not from switching off after charging.

Related Guides

Sources

Ofgem, "Default Tariff Cap" (June 2026: 24p/kWh standard electricity, 6p/kWh gas).
Energy Saving Trust, "Storage Heaters" guidance (running cost calculations and property-type comparisons, 2026).
Which?, "Storage Heaters: Are They Worth It?" (old vs modern model comparison, 2025).
BEAMA, "Guide to Electric Heating" (Economy 7 and Economy 10 tariff structures, 2024).
Citizens Advice, "Storage Heaters" (input and output control explainer, 2025).

Last reviewed: 2026-06-27