How do I use an electric heater safely?

A portable electric heater turns 2 or 3 kilowatts into heat in a small volume, which is a large amount of energy in a very ordinary-looking object. Fire services publish the same causes every winter, and they are almost all about proximity and supply: something soft too close, something laid over the top, and a plug drawing 13 amps continuously through a lead that was designed for occasional light loads. None of them is about the heater failing. Which is why the rules below are worth following even with a new, well-made appliance.

Safety

What you'll need

• A wall socket within reach of the heater's own flex
• A hard, level floor position clear of furniture
• A smoke alarm in that part of the house, tested

Step by step

1. Plug it directly into a wall socket.Not an extension lead, not a reel, not a multi-way adaptor, not a travel adaptor, and not sharing a socket with anything else substantial. A heater draws close to the maximum a socket is designed for, continuously, and extension leads are the single most common failure point. If a reel is unavoidable in a workshop, it must be fully unwound and rated for the load — but the correct answer is a socket.
2. Give it a metre of clear space on every side.Curtains, bedding, sofas, cushions, drying racks, cardboard, newspapers and dog beds. Check above it as well as around it — curtains and a low shelf are both above a heater standing against a wall.
3. Never cover it and never dry clothes on it.This is the most common single cause. Covering a heater traps the heat it is designed to shed, and a garment draped over a convector or oil-filled radiator sits directly in the hottest airflow. Use an airer in another part of the room, well clear, or a dehumidifier.
4. Switch it off when you leave the room and when you go to bed.No portable heater should run unattended overnight or in an empty house. If the reason you want it on overnight is a cold bedroom, a correctly used electric blanket, better curtains and draught-proofing are the safe answers.
5. Stand it on a hard, level surface where it cannot be knocked over.Not on carpet where it can sink and tip, not on a rug that can bunch, and not where a door swings or a pet or child moves past. Most modern heaters have a tip-over cut-out, which is a backup rather than a permission.
6. Check the flex and plug every time you get it out of storage.Run the flex through your fingers for cuts, crushing, hardening and kinks near the plug. Look at the plug pins for discolouration or pitting. Feel the plug after ten minutes of running — it should be at most slightly warm. Warm, browned or smelling means stop and do not use that socket either.
7. Expect a burning smell only on the first use of the season, and only briefly.Dust settled on the element burns off in the first ten or fifteen minutes, and that is normal. A smell that persists, returns each use, or smells of hot plastic rather than dust is a fault. Stop using it.
8. Know the specific risk of your heater type.Fan heaters: the intake grille clogs with dust and fluff and then the element overheats, so vacuum it. Halogen and radiant heaters: the element surface is genuinely hot enough to ignite fabric at close range, so distance is critical. Oil-filled radiators: the surface stays hot long after switching off, and the oil is not user-serviceable — a leaking one is scrap. Convector and panel heaters: the top vent must never be used as a shelf.
9. Keep them out of bathrooms and away from water entirely.A portable heater must never be used in a bathroom or shower room. Heating in those rooms is a fixed appliance, chosen for the zone and installed by a qualified electrician. The same applies to any wet area — a utility room sink, a garage with a floor that gets washed down.
10. Use a thermostat and a timer, which is also a safety measure.A heater cycling under a thermostat runs cooler and for less time than one held at full output, and a timer means it cannot be left on by accident. It saves money and it reduces exposure at the same time.
11. Buy from a reputable retailer and register the appliance.Heaters have been subject to safety recalls. Registering it with the manufacturer is how you get told. Avoid unbranded imported heaters from marketplace sellers, where the safety marking may mean nothing.

Tips

• The plug test is the most useful habit: touch the plug after ten minutes. Cool or slightly warm is fine; anything more is a warning about the socket, the plug or the load.
• Vacuum the grilles of a fan heater at the start of each season. A clogged intake is what makes the element overheat, and it is entirely preventable.
• If you find yourself wanting a heater on all night, that is a signal to spend the money on draughts, curtains and an electric blanket instead — cheaper to run and far safer.
• Test the smoke alarm in that part of the house before the first cold snap, not after.

Common mistakes

• Drying clothes on or in front of a heater — It is the classic cause of portable heater fires. The fabric traps heat against the appliance and can ignite, and it also blocks the airflow the heater relies on to shed its own heat.
• Using an extension lead because the socket is inconveniently placed — A heater is a sustained near-maximum load. Extension leads and reels are not designed for it, they overheat at the plug and the coil, and this is a leading cause of electrical fires.
• Leaving one running in a bedroom overnight — Nobody is awake to notice a fault, a fallen item or a tip-over, and a bedroom is full of soft furnishings. No portable heater should run unattended overnight.
• Buying an unbranded heater from an online marketplace — Safety markings on unbranded imports are frequently meaningless, and there is no recall route if a fault emerges. This is a category where the brand and the retailer genuinely matter.

If it doesn't work

Questions people ask