Electric Baseboard Heater Not Working or Not Getting Hot
By Ray Bennett · Updated 2 October 2026 · 9 min read · Checked against the maker’s manual 
Turn its thermostat all the way up and give it 3 to 5 minutes. If nothing happens, check that heater's breaker, then look for anything blocking it, because a heater that got too hot shuts itself off and resets once cool. A heater that only gets warm, most of all one just put in, can be a 240 volt heater on a 120 volt circuit, or a 240 volt circuit only half working: a job for an electrician.
An electric baseboard heater has very few parts: a breaker, a thermostat, the wires, a safety shutoff and the heating element. When one stops heating, the makers’ troubleshooting charts point to those.
Most of the checks need nothing but your eyes and the thermostat knob. Anything inside the heater or the panel is an electrician’s job.
Before you start
What to carry: a torch, and your phone to photograph the label on the heater. Ten minutes, plus a few minutes of waiting after each change.
Gas, oil or electric? This page is about electric baseboard heaters: a long metal box along the wall with no pipes, wired straight into the house. If your baseboard has water pipes and runs off a boiler, it is hot water baseboard: hot water radiators and baseboard.
Know your voltage. Cadet says to read the label on the heater: 120 volt heaters run on a single pole breaker, 240 volt heaters on a double pole breaker.
Never bypass the safety shutoff. Cadet says do not tamper with the high temperature safety shutoff, and King says removing or bypassing it could make the heater a fire hazard.
A heater glowing red, or one that keeps overheating and shutting off. Cadet says to turn off its circuit breaker immediately and check the voltage on its label, because a heater on a higher voltage than its label can start a fire. Leave it off and call an electrician.
Where the power stops
Turn the thermostat all the way up, and wait
The test. First move anything touching or covering the heater, because Cadet says blocking it can start a fire. Cadet’s instructions for a dial thermostat are to turn the knob all the way to the right, then back to the left until it clicks once the room is warm. In the check King and Marley give for a newly installed system, every heater should be working 3 to 5 minutes after its thermostat is turned to the highest setting.
Where the thermostat is. Cadet says it is either on the wall or on the heater itself. Marley recommends no more than one thermostat in each room, and Cadet says every heater on one thermostat must be in the same room as it. So when one room is cold, start with that room’s thermostat.
No off position. Dimplex and Marley say a single pole thermostat has no off setting, and Marley says it will keep heating below its lowest setting. Dimplex says power runs to the heater all the time, so only the breaker turns it fully off. A double pole thermostat has a real off position.
A digital thermostat. Cadet says to follow the guide that came with it. Honeywell says its RLV4300 must be in automatic mode to follow its schedule, and that a housing that feels hot is normal, as long as the heaters on it do not exceed its maximum load.
Check that heater's breaker
Its own circuit. Cadet says electric heaters must be on a circuit used only for heaters, never shared with outlets, lights or other appliances, so look for the breaker labeled for that room’s heat.
A breaker that has tripped. King lists three causes of a heater breaker that trips: a short circuit, too much load on the circuit, and the wrong voltage. All three are jobs for an electrician. To reset it once, turn the thermostat down first, then push the breaker fully off and back on. If it trips again, leave it off and call an electrician. More on that: a breaker that keeps tripping.
A breaker that will not stay on, or a heater that stays dead. Cadet’s answer for a faulty circuit breaker is a licensed electrician. Cadet’s other cause of a heater that does not work at all is a loose supply connection inside the heater or at the wall thermostat, which is tightened with the power off at the panel: an electrician’s job. King adds that a 240 volt heater needs its double pole breaker connected properly in the panel to get 240 volts.
Look for anything blocking it
Why it shuts off. Cadet says every baseboard heater has a high temperature safety shutoff that cuts the power if the inside gets too hot, and it resets itself after cooling. King says its safety limit turns the heater off when it is blocked or overheats, and should not operate in normal use.
The clue on a digital thermostat. Honeywell says that if its RLV4300 shows LP or goes blank when the power is not out, the heater’s thermal cutout has opened. The heater may have been blocked by furniture or a curtain and overheated, or the cutout itself may be faulty or too sensitive.
What to clear. Pull furniture, beds, curtains, bedding and clothes away from it, then give it time to cool and reset. Cadet says the heater is hot when in use, so keep bare skin off it, take extreme care when children are near it, and never let anything be pushed into its openings, which can cause a shock or fire.
The makers’ numbers. Cadet asks for at least 12 inches clear above and in front of the heater and 6 inches at each side. King asks for at least 6 inches between furniture and the heater, and says curtains must not touch it. Cadet and King also say a heater must not be installed below a wall outlet. Dimplex says its clearances are part of the safety approval, and ignoring them is unsafe. NFPA’s general rule for heating equipment such as a furnace, fireplace, wood stove or space heater is to keep anything that can burn at least three feet away.
If it keeps shutting off. King says that if the safety control keeps cycling the heater off with nothing blocking it, turn the power off and have it checked by a qualified electrician.
Clean the dust out
Why. King says dust collects between the fins of the element, and lists a heater that needs cleaning as one cause of a heater that smokes. Cadet says to clean the heater at least every 24 months.
Cadet’s steps. Make sure the power is off at the panel, not just the thermostat turned down, and the element is cool. Wipe the cover with a damp cloth and dry it, then vacuum with an attachment without touching the element, and turn the power back on. King warns the fins are sharp, so avoid touching them.
A smell on the first run. King says it is normal for a new heater to burn off a light oil from the factory the first time it runs, and that windows should be opened until it stops. Cadet says to run a new heater on its highest setting for 30 minutes after installing it, when some smoke may come off.
It runs, but only gets warm
The wrong voltage. Cadet’s troubleshooting table lists a 240 volt heater on a 120 volt circuit as one reason a heater does not get hot. Cadet also says a heater on a voltage higher than its label will be destroyed and could start a fire. Compare the label on the heater with the breaker: one pole for 120 volts, two for 240.
Half of a 240 volt circuit. Dimplex says the most common reason a 240 volt heater that has just been hooked up does not work, or is barely warm, is a fault in the 240 volt connection at the electrical panel. An electrician checks it with a meter across both supply wires, which should read 240 volts.
Two heaters wired one after the other. Cadet lists baseboard heaters wired in series as another cause of heaters that do not get hot. They should be wired in parallel, an electrician’s fix.
Too small for the room. Cadet lists a heater too small for the room as a reason it never shuts off. Dimplex’s rule of thumb is about 10 watts per square foot in a standard insulated room, so a 1,000 watt heater for 100 square feet.
Other things the makers list
It will not turn off. Besides a heater too small for the room, Cadet’s causes are a faulty thermostat, which is replaced, or no thermostat connected at all: Cadet says every baseboard heater needs one. A single pole thermostat has no off position, so the breaker is the way to turn it off.
The room never matches the setting. King says sunlight or another heat source can fool the thermostat, so move the heat source, or have an electrician move the thermostat, and that a room swinging from too hot to too cold points to a poor thermostat. Honeywell says a draft, or a heat source near it such as a light dimmer, can make its thermostat show the wrong temperature.
Creaking, popping or humming. Cadet says the heater’s cabinet may need a slight adjustment, and to call its technical support.
Rooms set differently with the doors open. Marley says this raises running costs and lowers comfort, and suggests keeping all thermostats at the same setting unless doors are closed. If the electric bill is what sent you here: a bill that suddenly jumped.
What each one costs
| The step | Cost |
|---|---|
| Thermostat turned up, breaker checked | Nothing |
| Furniture and curtains moved, dust vacuumed | Nothing |
| A new thermostat | The price of the thermostat, fitted by an electrician |
| Wiring, voltage or a breaker that keeps tripping | An electrician’s visit |
Questions people ask
Why is my baseboard heater not working in one room?
Marley recommends no more than one thermostat in each room, so start with that room’s. Turn it all the way up and wait 3 to 5 minutes, check the breaker for that heater, and move anything blocking the heater so its safety shutoff can reset.
Why is my baseboard heater not getting hot?
Cadet lists a 240 volt heater on a 120 volt circuit, and heaters wired in series. Dimplex says a 240 volt heater that is barely warm just after it was hooked up most often has a fault in its 240 volt connection at the panel. All three need an electrician.
How do I reset a baseboard heater?
Cadet says the high temperature safety shutoff resets itself once the heater cools. Clear whatever blocked it and wait. If it trips again and again, King says to turn the power off and call a qualified electrician.
Why does my baseboard heater turn on and off by itself?
The thermostat switching it on and off is normal. If it shuts off while the room is still cold, the safety shutoff may be tripping because the heater is blocked, and Honeywell adds that the cutout itself can be faulty or too sensitive.
How close can furniture be to a baseboard heater?
King’s minimum is 6 inches, and Cadet asks for 12 inches clear above and in front. Curtains must not touch it. Follow the numbers in your own heater’s manual, and NFPA’s general rule is to keep anything that can burn at least three feet from heating equipment.
Is it normal for the thermostat to feel warm?
On Honeywell’s RLV4300, yes. Honeywell says a hot housing on its line voltage thermostat is normal, as long as the heaters on it do not exceed its maximum load.
The other electric heat guides: a baseboard heater that will not turn off, a baseboard heater making noise, an electric wall heater not working, a space heater not working and an electric heater that smells like burning.
Sources: Cadet electric baseboard heater owner's guide 720001, Dimplex electric baseboard heater guide 720001 and Dimplex electric heater technical support page, King Electrical K Series baseboard installation and troubleshooting chart, Marley 2500 Series wiring instructions and Qmark TA line voltage thermostat instructions, Honeywell Home RLV4300 line voltage thermostat owner's manual 33-00150, and NFPA heating safety tip sheet
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