The short answer
A space heater is fine for one room while you’re in it. Here in Northern Virginia, we’d keep it three feet from anything that burns, plug it straight into the wall, and turn it off when you leave or go to bed. Those are the National Fire Protection Association’s rules. And if you’re running one every night because a room won’t warm up, that’s a ductwork or furnace problem wearing a disguise.
What we won’t do with a space heater
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| We won’t | Why |
|---|---|
| Plug it into a power strip or extension cord | A 1,500 watt heater pulls about 12.5 amps for hours. That’s a lot for a strip or a light cord. Straight into the wall. |
| Share the outlet’s circuit with a microwave or hair dryer | A normal 15 amp circuit has room for the heater and not much else. A tripping breaker is telling you something. |
| Run it while we sleep | NFPA says off at bedtime. Blankets fall, and cats move things. |
| Leave the room with it on | Same rule. It takes a minute to walk back and turn it on again. |
| Set it on a table or a thick rug | Hard, flat floor only. Keep it from tipping and blocking its own air. |
| Dry clothes or boots on it | Anything on the heater is what catches. |
| Buy one without tip-over shutoff | Look for the shutoff and a testing lab’s label, like UL, on the box. |
| Burn kerosene or propane in a closed room | Anything burning fuel inside needs to be made for indoor use and vented right. Carbon monoxide doesn’t announce itself. |
The $67 Heating Check
We check your furnace, heat pump or boiler before winter. Through December 31. See the offer
Signs to stop using it
Stop and unplug it if the plug or the outlet is hot to the touch, if the cord looks melted or browned, if you smell something like hot plastic, or if the breaker keeps tripping. Don’t plug it back in somewhere else to see what happens. A warm plug that’s discolored means that outlet needs an electrician.
Put working carbon monoxide and smoke alarms on every level. If a CO alarm goes off, get everyone outside and call 911, then read this.
The trick nobody mentions: the thermostat
Your thermostat reads one spot. Put a space heater in the room with it, and the thermostat decides the house is warm and shuts the furnace off. The bedrooms cool down, you buy a second heater, and the bill climbs. Keep it far away from the thermostat. Here is what to set that thermostat to.
If you’re using one because something’s wrong
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| What’s happening | What it usually means |
|---|---|
| One room is always cold | Long duct run, a leak in the duct, or a room over a garage. How to track it down, and zoning or ductless if it’s permanent. |
| The whole house can’t hold temperature on the coldest days | Why a furnace can fall behind. Could be a filter, could be the system’s size. |
| The heat is out | Fine for a night while you get help. Check these first, and if pipes are at risk, read this. |
| The power is out | A space heater won’t run anyway. What to do for heat and pipes. |
Using one to thaw a pipe
You can warm a cold room with one, watched, three feet back. Don’t aim it at a wall and leave. The Red Cross’s safe list for the pipe itself is a hair dryer, heating pad or hot towels. What not to do with a frozen pipe.
What it costs to run
A 1,500 watt heater on high uses 1.5 kilowatt hours for every hour it’s on. Find the rate on your electric bill and multiply. Eight hours a night, night after night, adds up fast, which is why heating one room can make sense for a short while and rarely all winter. Other ways to bring the heating bill down, and the rest of our winter list.
Book it
If a space heater has become part of how your house stays warm, have someone look at why. The heating check is $67 per system through December 31, on a furnace, heat pump or boiler. Book it from goswiftpro.com/cookiesoffer and free MOLTN cookies come with the visit. Or call (703) 997-9757. SwiftPro is rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook, Virginia Class A license 2705192276.
Questions people ask
Is it safe to leave a space heater on overnight?
No. The National Fire Protection Association says turn it off when you leave the room or go to bed. Use extra blankets, or get the real heating problem looked at.
Can you plug a space heater into a power strip?
No. NFPA says plug it directly into the wall. A typical 1,500 watt heater pulls about 12.5 amps, and strips and light extension cords can overheat at that load.
How far should a space heater be from furniture?
Three feet from anything that can burn: curtains, bedding, chairs, paper, and people’s clothes.
Why does my house get colder when I use a space heater?
If the heater warms the room with the thermostat, the thermostat thinks the house is warm and shuts the furnace off, and the rest of the house cools down. Keep it away from the thermostat.
