Choosing the right heater comes down to two things: how the space is being heated and how often. A portable electric convector costing £30 is the right answer in dozens of situations. A heat pump costing £10,000 after the grant is the right answer in others. Getting this decision wrong doesn’t just mean paying more — it means either running a heater that can’t cope or paying through the nose for warmth you could get much cheaper with a different approach.
This guide covers every main heater type available in the UK, how each works, what it costs to run, and when it makes sense to use it.
Contents
- 1 Key Takeaways
- 2 Types of Electric Space Heaters
- 3 Running Costs by Wattage
- 4 Room Size Guide
- 5 Storage Heaters
- 6 Gas and Oil Heaters
- 7 Heat Pumps
- 8 Underfloor Heating
- 9 Portable and Specialist Heaters
- 10 Case Study: Supplementary Heating for a Victorian Terrace in Sheffield
- 11 Expert Insights From Our Heating Engineers About Heater Types
- 12 Frequently Asked Questions
- 12.1 What is the cheapest type of heater to run in the UK?
- 12.2 What size heater do I need for my room?
- 12.3 Are infrared heaters better than convector heaters?
- 12.4 What is the difference between a convector heater and a fan heater?
- 12.5 Are storage heaters worth it in 2026?
- 12.6 Are electric heaters safe to leave on overnight?
- 13 Summing Up
Key Takeaways
- All direct electric heaters are 100% efficient at converting electricity to heat — the differences between types are about speed, heat distribution, and running behaviour, not efficiency
- At the current UK electricity rate of approximately 24.7p/kWh, a 2kW electric heater costs around 49p per hour at full output
- Heat pumps are the exception to the electric heater rule: they produce 2.5 to 4 units of heat per unit of electricity, making them far cheaper to run than direct electric
- Gas central heating remains the cheapest whole-home option for the majority of UK homes connected to the gas grid — roughly 6.5p per kWh of useful heat versus 24.7p for direct electric
- For supplementary or occasional heating, an oil-free electric radiator with a thermostat is the best general-purpose choice for most UK rooms
- Storage heaters on Economy 7 or Economy 10 tariffs offer significantly cheaper overnight charging rates — useful for homes off the gas grid with predictable daily routines
- Infrared heaters warm people and surfaces directly rather than air — better in draughty spaces and outdoors where heated air escapes
Types of Electric Space Heaters
Electric space heaters cover everything from basic plug-in convectors to smart-controlled panel heaters. They all convert electricity to heat at 100% efficiency — what varies is how they deliver that heat, how quickly, and how suitable they are for sustained use versus quick warm-ups.
Convector Heaters
Convector heaters draw cool air in through the base, pass it over a heating element, and push warm air out through the top via natural convection. They heat a room quickly because they circulate warm air rather than waiting for surfaces or oil to warm up first. Most are lightweight, inexpensive, and portable.
Running cost: At 24.7p/kWh, a 2kW convector costs 49p/hour at full output. In a well-insulated room with a thermostat cycling on and off to maintain temperature, typical effective hourly costs drop to 20–30p.
Best for: Quickly warming a room you’ve just entered. Not the best choice for all-day background warmth — oil-free or oil-filled radiators are better for that.
Examples on this site: best convector heaters
Fan Heaters
Fan heaters work like convectors but with a fan that forces air across the element. They heat a room faster because the fan distributes warm air more aggressively. The trade-off is noise — they’re not suitable for bedrooms during sleep, and the airflow can feel uncomfortable at close range.
Running cost: Identical to convectors at the same wattage. Wattage determines cost, not the mechanism.
Best for: Quick bursts of warmth in bathrooms, garages, or anywhere you need heat fast and noise isn’t a concern.
Examples on this site: best fan heaters
Oil-Filled Radiators
Oil-filled radiators contain sealed columns of thermal oil that slowly absorbs heat from an electric element — typically 30–45 minutes to reach full output. The benefit is heat retention: once the oil is hot, the thermostat cycles off for longer periods because the oil continues radiating warmth after the element switches off.
They run silently and produce even, gentle warmth very similar to a central heating radiator.
Running cost: The same per kilowatt-hour as any other electric heater — but the heat retention means the element runs for a smaller proportion of each hour once the room is up to temperature, reducing average energy use for sustained heating.
Best for: All-day background warmth in bedrooms, offices, or living rooms. A poor choice if you only need the room warm for 20–30 minutes — the slow warm-up wastes that heat retention advantage.
Examples on this site: best oil-filled radiators
Oil-Free Column Radiators
Oil-free radiators use glycol fluid or direct-element heating technology instead of thermal oil. They reach working temperature in 5–10 minutes rather than 30–45, combining faster response with the gentle, even heat of radiator-style output. They’re the best general-purpose electric radiator for most UK rooms — responsive enough for rooms used intermittently, efficient enough for extended use.
Best for: Most domestic use cases. If you only buy one electric heater, this is usually the right category.
Examples on this site: best oil-free radiators
Panel Heaters
Panel heaters are slim, flat units designed primarily for wall mounting, though most also stand freestanding. They produce mainly convective heat from a flat panel and are popular for their unobtrusive appearance. Most modern models include digital thermostats and WiFi control via app, making them easy to schedule precisely.
Best for: Bedrooms, home offices, and spaces where aesthetics matter and you want a wall-mounted permanent solution with programmable control.
Examples on this site: best electric panel heaters
Infrared Heaters
Infrared heaters emit electromagnetic radiation that warms people, furniture, and surfaces directly, rather than heating the surrounding air. This makes them feel warmer than the air temperature might suggest, and they’re effective in draughty spaces where warm air would escape before reaching you. They’re the dominant choice for outdoor and semi-outdoor use.
Running cost: 24.7p/kWh like all electric heaters — but because you’re being warmed directly rather than through air, you often need less wattage to feel comfortable in a draughty space.
Best for: Patios, workshops, covered outdoor areas, garden rooms, and any space with poor insulation where heating the air would be wasteful.
Examples on this site: best infrared heaters
Halogen Heaters
Halogen heaters use halogen bulbs as heating elements, producing bright, immediate, directional radiant heat. They’re the cheapest to buy and heat a specific spot almost instantly. The bright glow is uncomfortable in dark rooms and they should never be left running unattended.
Best for: Quick personal warmth in a workshop or garage while you’re working nearby. Not suitable for unsupervised or overnight use.
Examples on this site: best halogen heaters
Running Costs by Wattage
All electric heaters cost the same per unit of electricity. The table below shows hourly running costs at 24.7p/kWh (UK average April–June 2026):
| Wattage | Cost per Hour (full power) | Typical Use Case |
|---|---|---|
| 500W | 12p | Small supplementary heater, bathroom |
| 750W | 19p | Small room up to 8m² |
| 1,000W (1kW) | 25p | Small room 8–12m² |
| 1,500W (1.5kW) | 37p | Medium room 12–18m² |
| 2,000W (2kW) | 49p | Medium–large room 18–25m² |
| 2,400W (2.4kW) | 59p | Large room or poorly insulated space |
| 3,000W (3kW) | 74p | Large room or garage |
These are full-power figures. A heater with a functioning thermostat won’t run continuously — in a well-insulated room, the element typically operates for 30–50% of the time to maintain temperature, roughly halving the effective hourly cost.
Room Size Guide
Matching output to room size is the most important decision when buying an electric heater. Undersizing means the heater runs constantly without reaching the target temperature; oversizing wastes money.
| Room Size | Recommended Output (well insulated) | Recommended Output (poorly insulated) |
|---|---|---|
| Up to 10m² | 700W–1kW | 1kW–1.5kW |
| 10–15m² | 1kW–1.5kW | 1.5kW–2kW |
| 15–25m² | 1.5kW–2kW | 2kW–2.5kW |
| 25–35m² | 2kW–2.5kW | 2.5kW–3kW |
| Garage / workshop | 2kW–3kW | 3kW+ |
Rooms with large windows, high ceilings, or external walls on multiple sides need more output. If in doubt, size up — a thermostat will manage the difference, but an undersized heater has nowhere to go.
Storage Heaters
Storage heaters charge overnight using cheaper off-peak electricity on Economy 7 or Economy 10 tariffs and release stored heat throughout the following day. The core contains dense clay or ceramic bricks that absorb large amounts of energy and release it slowly as radiant and convective heat over 12–16 hours.
The overnight Economy 7 rate is typically around 9–11p/kWh — roughly a third of the standard daytime rate. This makes storage heaters significantly cheaper per unit of heat than daytime electric heaters for homes that can use them effectively.
Running cost: Approximately 10–13p/kWh of heat delivered, depending on overnight tariff and system efficiency.
Best for: Homes off the gas grid with predictable heating patterns — charging overnight, releasing heat during the day. Less suitable if your schedule varies significantly, since once the stored heat is released you can’t get more until the next overnight charge.
Examples on this site: best electric radiators
Gas and Oil Heaters
Gas Central Heating
Gas central heating — a gas boiler circulating hot water through radiators — remains the cheapest whole-home heating option for the majority of UK homes on the gas grid. At roughly 5.9p/kWh for gas, and with a modern condensing boiler operating at 90%+ efficiency, useful heat costs around 6.5p/kWh. That’s less than a quarter of the cost of direct electric heating.
If you have gas and your boiler is less than 15 years old and well-serviced, it remains the most cost-effective way to heat your home. See our central heating guide for system types and maintenance detail.
Running cost: ~6.5p per kWh of useful heat from a modern condensing boiler.
Gas Space Heaters
Freestanding and wall-mounted gas space heaters — flueless or flued — heat individual rooms without a central system. Flueless models require well-ventilated rooms and are not permitted in bedrooms. Flued models connect to an external wall or flue.
Best for: Off-grid properties using LPG, or supplementary heating in rooms that central heating doesn’t adequately cover.
Examples on this site: best gas heaters
Heat Pumps
Heat pumps are fundamentally different from every other heater on this list. Rather than converting electricity to heat at 1:1, they move heat from outdoor air or the ground into your home. For every 1 kWh of electricity, a heat pump delivers 2.5 to 4 kWh of heat.
At current electricity prices, a heat pump with a Seasonal Coefficient of Performance (SCOP) of 3.5 produces heat at roughly 7.9p/kWh — broadly comparable to a gas boiler, and significantly cheaper than oil or LPG.
The upfront investment is substantial (£9,000–£17,000 installed for air source before the grant), but the Boiler Upgrade Scheme offers £7,500–£9,000 towards installation depending on your current fuel type.
Best for: Whole-home heating as a replacement for gas, oil, or LPG, particularly in well-insulated properties with large radiators or underfloor heating.
Underfloor Heating
Underfloor heating distributes heat across the entire floor surface, warming a room from below. Wet systems pipe hot water under the floor connected to a boiler or heat pump; dry electric systems use cables or mats under the floor covering.
Wet UFH runs at lower water temperatures than radiators (typically 35–45°C), which makes it ideal for heat pumps. Electric UFH is simpler to install but more expensive to run at standard electricity rates.
Best for: Extensions, new builds, or renovations where underfloor installation is practical. Particularly well-matched to heat pumps.
Examples on this site: best underfloor heating kits
Portable and Specialist Heaters
Patio Heaters
The main types are freestanding gas patio heaters (using propane cylinders) and infrared electric models. Gas heaters produce higher heat output but need gas cylinders replaced or refilled. Electric infrared models are more convenient and can be wall-mounted.
Examples on this site: best patio heaters
Greenhouse and Shed Heaters
Small electric fan heaters with frost protection settings (activating at 5°C or below) are the most practical choice. Look for IP-rated models designed for damp environments.
Examples on this site: best greenhouse heaters | best shed heaters
Plinth Heaters
Plinth heaters fit into the kickboard beneath kitchen or bathroom units, blowing warm air into the room at floor level. A practical space-saving solution where wall or floor space is unavailable.
Examples on this site: best plinth heaters
Case Study: Supplementary Heating for a Victorian Terrace in Sheffield
Background
A homeowner in Sheffield had gas central heating that kept the main living areas comfortable but left the rear kitchen extension — added in the 1990s — noticeably cooler. The extension had two radiators that struggled on the coldest days.
Project Overview
Rather than extending the central heating pipework (disruptive and expensive), the homeowner wanted a low-cost supplementary heater: no installation needed, programmable, and unobtrusive.
Implementation
A 2kW oil-free column radiator with a 24-hour programmable timer was placed in the dining area. The timer was set to run for two hours before dinner and switch off automatically. On the coldest mornings it was also set for two hours in the morning.
Results
The extension maintained a comfortable temperature throughout winter without affecting the main central heating bill. Estimated running cost over the heating season: approximately £89, based on roughly 90 hours of element-on time at 24.7p/kWh for 2kW.
Expert Insights From Our Heating Engineers About Heater Types
One of our senior heating engineers with over 15 years of experience in domestic heating installations shared his perspective.
“The question I get asked most often is which electric heater is cheapest to run. They all cost the same per kilowatt-hour — it’s the wattage and the hours of use that determine your bill, not the type. What changes is how long you need to run them. An oil-free radiator reaches temperature in 10 minutes. An oil-filled one might take 45. If you only need the room warm for an hour, the oil-free option means less total running time. If you’re heating all day, the oil-filled one’s heat retention is the advantage.”
“People consistently undersize heaters and then wonder why the room never warms up properly. They buy a 1kW heater for a 20m² room because it’s cheaper and then run it all day achieving nothing. Buy the right wattage for the space — the thermostat manages the rest. A correctly sized heater that cycles on and off to maintain temperature uses far less energy than an undersized one running continuously at full power.”
“If you’re using an electric heater as your main heat source and your bills feel excessive — check two things. First, is there a thermostat, and is it set correctly? Second, is the room’s insulation adequate? An electric heater in a poorly insulated room is an expensive way to heat the outside.”
Frequently Asked Questions
What is the cheapest type of heater to run in the UK?
For whole-home heating, gas central heating is cheapest at roughly 6.5p per kWh of useful heat. For properties off the gas grid, a well-specified heat pump is the next cheapest at around 7.1–8.2p/kWh depending on SCOP. All direct electric heaters cost the same at approximately 24.7p/kWh. Storage heaters on Economy 7 tariffs reduce this to around 10–13p/kWh by using cheaper overnight electricity.
What size heater do I need for my room?
A rough guide for well-insulated rooms: 700W–1kW for up to 10m², 1–1.5kW for 10–15m², 1.5–2kW for 15–25m², and 2–3kW for larger or poorly insulated spaces. Rooms with large windows, high ceilings, or multiple external walls need more. If you’re between sizes, choose the higher wattage — the thermostat will manage how often the element runs.
Are infrared heaters better than convector heaters?
They suit different situations. Infrared heats people and surfaces directly — effective in draughty, poorly insulated, or outdoor spaces where warm air escapes quickly. Convectors heat the air in a room, working better in well-insulated enclosed spaces. For a covered patio or draughty workshop, infrared wins. For a well-sealed bedroom or home office, a convector or oil-free radiator is typically more effective and more comfortable.
What is the difference between a convector heater and a fan heater?
A fan heater has a fan that forces air across the element — faster room warm-up, more aggressive heat distribution, and more noise. A convector relies on natural convection: warm air rises from the element and cooler air flows in to replace it, more slowly and silently. Fan heaters are better for rapid warm-up. Convectors are quieter and better for sustained background warmth.
Are storage heaters worth it in 2026?
They’re worth it for homes on Economy 7 tariffs with predictable heating patterns. Charging overnight at 9–11p/kWh and releasing heat during the day is significantly cheaper than running a standard electric heater at 24.7p/kWh. The limitation is inflexibility — once the stored heat is released, you can’t get more until the next overnight charge. For properties that can plan around this, they remain a cost-effective option for off-grid homes.
Are electric heaters safe to leave on overnight?
Oil-filled and oil-free radiators with functioning thermostats are designed for extended use and are generally safe overnight when placed away from curtains and bedding, with the thermostat set rather than left on maximum. Fan heaters and halogen heaters are not suitable for unsupervised or overnight use. Always check your specific model’s guidance. Using a timer to limit operation during sleeping hours is both safer and more energy-efficient.
Summing Up
The right heater type depends on how you’re using it. For occasional room top-ups, an oil-free radiator or convector with a thermostat handles most situations well and won’t cost much to run. For whole-home heating, nothing currently beats gas central heating on running costs for homes on the grid — though a well-specified heat pump is now close, and significantly ahead for oil and LPG properties.
Match the wattage to your room, use the thermostat rather than running on maximum, and buy a heater designed for the type of use you have in mind. The differences between heater types matter less than those two decisions.
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