Portable electric heaters draw far more current than a smart bulb or a phone charger, and that changes what you should look for in a smart plug for an electric heater. Plenty of budget smart plugs on the market are only rated for lighting-level loads, and running a 2kW fan heater through one for hours at a time is exactly the kind of use that trips overheating and, in rare cases, causes fires. This guide covers what a safe smart plug actually needs to support, which models are rated for it, and how to add proper energy monitoring for a heater in Home Assistant.
Is it safe to run an electric heater through a smart plug?
It can be, but only with the right plug and the right setup. A standard UK BS 1363 socket is rated to 13A, which at 230V works out to just under 3,000W — comfortably enough for most portable heaters, which typically draw 1,500–2,500W. The smart plug itself needs to match that rating, not just the wall socket. TP-Link's Tapo P110, for example, is officially rated to a maximum load of 2,990W at 13A, while Meross's MSS310 is rated to 13A on its UK variant — both close to the ceiling a UK socket allows.
The bigger risk is less about the smart plug itself and more about how heaters get plugged in generally. The London Fire Brigade names overloaded sockets as one of the most common causes of electrical fires in the home, and specifically warns against putting high-current appliances like kettles, tumble dryers or heaters on an extension lead or multi-way adapter. Their guidance is clear that higher-demand appliances need a 13A-rated connection, not a 3A one designed for lamps and electronics. The rule for a smart plug and a heater is the same one that applies to any heater: plug it directly into a wall socket via a single, properly rated smart plug — never into an extension lead, a plug-in adapter, or a smart plug that's daisy-chained off another device.
What to check before buying
- Maximum load rating. Look for an explicit 13A (or ~3,000W) UK rating in the spec sheet, not just a generic "10A" rating aimed at lighting loads. Several cheaper smart plugs cap out at 10A/2,300W, which is too close to the limit for a 2kW+ heater running for hours.
- No motor/compressor restriction that also blocks resistive heating loads. Some plugs restrict motorised appliances (like air conditioners) above a certain horsepower — this doesn't affect a resistive electric heater, but check the exclusion list in the manual to be sure your heater model isn't listed.
- Energy monitoring. A heater is one of the most expensive things you can leave running by accident. A plug with built-in wattage/kWh monitoring lets you see exactly what it's costing and catch it if it's been left on.
- Physical build. A plug that gets warm to the touch under load, has a loose UK pin fit, or lacks a manufacturer-published wattage rating at all is not worth the saving.
Best smart plugs for an electric heater in the UK
TP-Link Tapo P110 — best for energy monitoring
The Tapo P110 is rated to 2,990W at 13A on its UK variant, with built-in energy monitoring that logs real-time wattage and historical kWh use in the Tapo app. It integrates with Home Assistant through the official Tapo integration, which is locally polled rather than routed through a third-party cloud bridge, so scheduling and automations keep working even if TP-Link's servers have an outage. At around £9–£13 depending on retailer, it's one of the cheaper options that still publishes a full wattage rating.
Meross MSS310 — budget pick with energy monitoring
Meross's MSS310 carries the same 13A UK rating and includes energy monitoring, usually at a lower price point than the Tapo P110. It works with Home Assistant either via Meross's cloud integration or the community meross_lan local integration (available through HACS), which polls the device on your local network instead of round-tripping to Meross's servers. It's a reasonable choice if you want a second or third monitored plug without paying Tapo pricing for each one.
Setting up heater monitoring in Home Assistant
Once a monitored smart plug is added to Home Assistant, you get live wattage and daily/monthly energy sensors for free — no extra hardware needed. Add the device's energy entity to the Home Assistant Energy dashboard to track exactly how much a heater is costing per day, and pair it with an automation that turns the heater off after a set number of hours to avoid it being left running in an empty room. For a full walkthrough of setting up the Energy dashboard with plug-level monitoring, see our Home Assistant energy monitoring guide.
Safety checklist
- Plug the smart plug directly into a wall socket — never into an extension lead or another adapter.
- Confirm the plug's published maximum load is at or above your heater's wattage, with headroom rather than running at the exact limit.
- Don't run a heater unattended overnight through a smart plug unless it also has its own physical thermal cut-off (most portable heaters do).
- Check the plug isn't warm to the touch after extended use — if it is, stop using it with that appliance.
- Use the smart plug's schedule or an automation to cap how long the heater can run continuously.
If you're shopping for smart plugs more broadly rather than specifically for a heater, our best smart plugs UK roundup covers lighter-duty options too. And if the heater itself needs replacing, our best electric radiators UK guide compares models with their own built-in scheduling.
