Space Heater Keeps Turning Off? What Each Shutoff Means

A portable electric heater has several ways to switch itself off, and they fall into two groups. The first group is comfort controls: a thermostat, a timer, an energy-saving mode. The second is safety devices: a switch that senses the heater has tipped, and a sensor that cuts the power when the inside gets too hot.

When a heater keeps turning off, the job is to work out which group you are dealing with. A comfort control is a setting to change. A safety device that keeps tripping is the heater telling you something is wrong.

Match the shutoff to the cause

Normal shutoffs

1. The set temperature was reached.Safe check

   A heater with a thermostat turns off when the room reaches the setting and comes back on when the room cools. De'Longhi describes this as the thermostat maintaining the heat by cycling the unit on and off. If the heater sits in a warm corner or near another heat source, it reaches its setting early. Raise the setting, or move it.

2. ECO mode.Safe check

   Energy-saving modes lower the power or stop the heat for a while. De'Longhi says that with its ECO plus function the appliance may switch to a lower heating power a few times per hour, and that this is normal. Dreo says that in ECO mode its heater turns off when the room temperature is reached and restarts when it drops.

3. A timer.Safe check

   If the heater always stops after the same number of hours, a timer is set. Look for a clock symbol on the display and cancel it.

4. The fan runs on after the heat stops.Safe check

   Honeywell says its heater fans keep blowing after the heat level is reached, and for a while after you press power off, to cool the internal parts. That is not a fault.

Safety shutoffs

1. The tip-over switch.Safe check

   Many heaters have a switch on the base that cuts the power when the heater is not level. On thick carpet, a rug or a bed, the switch may not be pressed in and the heater will not run. Honeywell says to place the heater on a firm, level, open surface and not on an unstable surface such as bedding or deep carpeting. On its heaters, a beep followed by no heat means the tip-over switch was activated: stand the heater upright and turn it on again.

2. Overheat protection.Safe check

   A sensor inside the heater cuts the power when it gets too hot, which usually means air cannot get in or out. De'Longhi says to make sure the heater is not covered and is free of objects for a 3 foot radius, then unplug it and wait 10 minutes before plugging it back in. Honeywell gives the same wait of at least 10 minutes after removing any obstruction. Check for a curtain against the back, a dusty intake grille, or a heater pushed against a wall.

3. Dust on the intake.Safe check

   With the heater off, unplugged and cool, wipe the intake grille with a soft, dry cloth. Dreo recommends cleaning its heaters at least once during the heating season and warns never to let water get inside.

4. A very warm room.Safe check

   Some heaters stop when the air around them is already hot. Dreo's ceramic heater stops heating and shows the code FF when the surrounding temperature is above 122°F, which can happen in a small closed space or next to another heat source.

If it will not turn on at all

• Check the outlet. Plug in a lamp. If the lamp does not work either, see an outlet that is not working.
• Check the breaker. If other things on the circuit went off at the same time, the breaker tripped. Honeywell notes that more than one heater on the same circuit can do this. Unplug other heavy loads on that circuit before you reset it. If it trips again with only the heater running, stop and read why a breaker keeps tripping.
• Reset the heater. Honeywell suggests unplugging the heater and leaving it unplugged for about 20 minutes, which can reset an internal breaker.
• Check the base. Make sure the tip-over switch on the bottom is pressed in by a flat floor.
• Plug it into the wall. The CPSC says to plug electric space heaters directly into a wall outlet, never into an extension cord or power strip. Dreo also advises against extension cords.
• Read the code. On Honeywell heaters E1 means the tip-over switch has malfunctioned and the heater can no longer be used. On Dreo’s ceramic heater E1 and E2 are temperature sensor faults. Codes differ by brand, so check your own manual.

Repair or replace?

Portable heaters are not built to be repaired at home, and the parts that fail are the ones that keep the heater safe. If a sensor code returns, a safety shutoff keeps tripping, or the cord or plug is damaged, replace the heater or use the maker’s warranty.

For other faults, such as cool air, odd smells, noise or error codes, see common space heater problems. Before you buy a bigger one, check what it will cost to run in how much electricity a space heater uses, and read the space heater safety rules on where a heater can and cannot go. If the lights dim each time the heater comes on, see why lights flicker.