How to fix a Honeywell Space Heater not working

Your Honeywell space heater is not working? In this article, we’re troubleshooting and fixing your Honeywell space heater using just a few targeted questions.

This article covers all of the most-used Honeywell space heaters, including the Honeywell tower space heaters (Slim and HeatGenius) and the smaller Honeywell heaters (the 360-degree and UberHeat). 

Don’t worry if you have a different Honeywell heater. Most Honeywell heaters work just the same internally. So, you can follow this guide regardless!

First off, let’s start with a why. As an engineer and heat-blogger, I am always surprised by the lack of real help you get with technical issues online.

You may find a fixing guide here and there, but all the tips are generic and not really helpful.

Here’s one example from Honeywell:

“Try unplugging the unit and leaving it unplugged for about 20 minutes. This should reset the unit.”

the official Honeywell website … not very helpful

That’s the poorest kind of advice. In my entire life, I’ve never fixed any power electronics (such as heaters) by “reset”. In the end, heaters are very simple devices. There is nothing to reset in them.

Resets only help with more complex devices such as computers.

That’s the advice you get from the manufacturer. There is no explanation, no troubleshooting, nothing.

It seems like they just want to sell you another heater.

Anyways, let’s try to get your Honeywell heater working again. But with some real troubleshooting!

How to fix a Honeywell space heater not working

There are different forms of a heater not working. Some heaters might not turn on at all. Others might turn on, but not blow any hot air.

I’ve got you covered with troubleshooting and fixing tips for all of these scenarios.

Quick answer: To fix your Honeywell heater not working, open its case and clean out all of the dust. Also, plug it in another wall outlet to eliminate a defective wall outlet as a possible cause. If it still doesn’t work, visually inspect the electronic circuitry and replace all burned parts.

Have a look at the questions below to find your specific issue:

Does the heater turn on?

Your heater is plugged into the wall outlet but doesn’t even turn on? If a device doesn’t turn on, the issue is always somewhere in the power chain: fuses & circuit breakers, wall outlet, power cord, or the electric power circuit board inside your Honeywell heater.

Let’s have a look at the simplest causes first.

Check for a blown fuse or tripped circuit breaker

Fuses and circuit breakers are safety mechanisms. When devices draw too much power from your home’s electric circuit, fuses and circuit breakers interrupt the power supply in order to stop overheating, cable meltdown, and in the worst case, a house fire.

Honeywell heaters always draw 1,500 Watts. Any home should be able to handle a single 1,500W unit.

But, for instance, running your Honeywell heater along with a computer and a TV can be too much for your circuit and blow a fuse.

To fix a blown fuse or a tripped circuit breaker, go to your home’s electric service panel. There, you see a bunch of circuit breaker switches (in newer homes) or fuses (in older homes).

Check whether any of the switches or fuses are triggered.

Then, reset the circuit breaker switch. If you find a blown fuse, replace it with a matching fuse. You can find them in hardware stores or online.

Check for a defective wall outlet

A possible, but unlikely issue is a broken wall outlet. Even though broken wall outlets are rare, I list them here for completeness. I want you to be able to troubleshoot any issue with your space heater!

A broken wall outlet is very easy to troubleshoot. Just take your Honeywell heater to another wall outlet and try to run it there.

If it works on another outlet, then the space heater works and the issue is your wall outlet.

Replace it!

And in the meantime, run your Honeywell heater off another wall outlet.

Fix the broken power cord

The power cord that connects your heater to the wall outlet might have a loose connection.

And now, we’re at a point where you have to open your Honeywell space heater for the first time!

To check whether your Honeywell space heater receives power from the wall outlet, open its case until you see the power electronics.

Many Honeywell heaters open from the bottom side. Depending on the model, you might have to open the backside.

On the electric circuit board, there should be contacts where your power cord connects to. Use a voltmeter, a multimeter, or any other measurement tool to check whether you have any voltage there.

If you don’t have any voltage where the power cord connects to the circuitry, the issue is likely a loose contact in the power cord.

To fix it, replace your Honeywell heater’s power cord. If you’re good at soldering, this should be no problem.

And, I’d say this is a great opportunity to get into soldering for the first time!

If you use your Honeywell heater with an extension cord, get a proper heavy-duty extension cord for space heaters.

Inspect the electric power circuitry

If none of the previous causes (fuses, circuit breakers, wall outlet, power cord) was the cause for your Honeywell space heater not turning on at all, there’s just one more possible reason: An issue in the power electronics.

To troubleshoot power electronics, always start with a visual inspection. Just have a look at the electronic circuit board sitting inside your Honeywell space heater.

Inspect the circuit board for blown or broken parts. There may be a burned resistor or a capacitor with burn marks around it.

Take at least 5 minutes to carefully inspect the entire circuit board. Sometimes, it takes a few minutes of staring until you see the issue.

If you can’t find any out-of-place-looking parts, then use a multimeter to trace voltages. Start from the connection point of the power cord and follow the voltage until you find the voltage drop.

Replace the part that causes the voltage drop. In some cases, the voltage drop may be caused by nearby parts.

You can double-check this by unsoldering the broken part and checking the circuit’s voltage.

In any case, to fix broken power electronics, you need soldering skills and you have to know the broken part.

Unfortunately, Honeywell doesn’t sell any electronic circuit replacement parts. But any brand’s replacement parts will do as long as you get the right specifications.

power module
That’s what the power module in most space heaters looks like. Usually, they have large cylindrical capacitors and one or multiple transformers (yellow).

Does the light / display turn on?

In this section, we’re covering potential causes of your Honeywell space heater turning on, but not doing anything. Only a light or a display turns on.

But neither the heating nor the fan activates.

Clean or replace the clogged air filter

The likeliest reason for the power light or display turning on, but not the heating, is that the air filter inside your Honeywell space heater is clogged.

Not all space heaters have built-in air filters. But most heaters that blow air have one.

When the air filter is clogged, two things happen:

Your fan has to exert a much larger force to blow air. So, it rotates slowly and with much higher friction. As a result, it does not blow any air. 

The other thing that can happen is that dust accumulates to a point where it reaches the fan blades and blocks the fan from rotating.

Your Honeywell heater activates the fan’s power supply and thinks it is rotating. But actually, nothing happens.

Fixing clogged air filters is easy. Open your Honeywell space heater’s case and take out all of the internal components until you can access the air filters.

The best solution is to replace the air filter entirely. If you can’t find fitting air filters, you can cut any regular air filter to size and then tape it inside your heater.

I know this is not the kind of neat advice you expect. But it’s what works!

Alternatively, you can clean your clogged air filters with a dry toothbrush. Do not use water to clean air filters. Filters are full of dust. In combination with water, they are a breeding ground for bacteria.

You’ll never get rid of the smell.

So, only dry brush dirty air filters.

Insert the air filter in your Honeywell space heater again. Your heater should work now!

Reset the triggered overheat protection

Many Honeywell space heaters have built-in overheat protection. Many space heaters from other brands rely on digital overheat protection. That’s basically a thermometer that monitors the temperature. And if it rises above a certain threshold, the thermostat cuts down the heating.

However, when the electric controls fail during an overheating, there’s nothing to stop the overheating.

So, Honeywell designed a mechanical overheat protection, which always works, even without electricity.

The mechanical overheat protection is a simple sheet metal contact in the side of the heater’s case, next to the air filter.

When your heater overheats, the heat-sensitive metal sheet deforms and opens the circuit, which cuts off the power supply.

I like it a lot, actually. Honeywell’s overheat protection is both simple and safe.

But there’s one disadvantage: The bent metal sheet does not move back into place when the heater cools down again.

Another problem is that the contacts can deform without overheating, for example when the heater tips over.

honeywell space heater overheat protection
The overheat protection is the small copper piece sitting aside the air filter. In the image it’s on the top right side of the air filter.

Here’s how to fix it.

Open your heater and check the inside of the case next to the air filter. There should be a copper-colored contact.

When this contact is open (meaning one metal sheet doesn’t touch the other), your heater can’t receive power.

Press the contact down, so both metal pieces touch. Then, try to run your Honeywell heater again. It should work now.

Theoretically, you can force the two metal contacts together with tape or a metal clip. But I recommend trying without since this would break the overheat protection.

By the way:

“Don’t test your Honeywell space heater fixes when your heater is lying on its side. The tip-over protection is active. Honeywell heaters only turn on when they’re upright.”

Does the heater blow only cold air?

In this section, we’re figuring out what to do when your Honeywell heater turns on but blows only cold air.

Test for a broken thermometer

Honeywell space heaters have a built-in thermostat. A thermostat is a temperature control device.

Depending on your room’s temperature, it activates or disables the heating.

So, it has to read your room temperature from a thermometer sitting inside your Honeywell space heater.

Usually, this thermometer sits in the bottom part of the case where it is not exposed to heat (since heat always rises up).

If the thermometer in your Honeywell space heater is broken and reads false or no temperatures, your heater won’t activate the heating element.

If your heater has a display with a temperature reading, then the thermometer is easy to test.

Open the bottom part of the case and locate the thermometer component. It’s a small circuit board (under 1 inch × 1 inch).

Touch it and see if the temperature displayed changes. If it doesn’t change, then the thermometer is broken.

Inspect the thermometer closely. See if all the wires are connected properly and if there are any blown parts.

You might be able to fix it without replacement if there is just a broken connection.

In any other case, replace the entire thermometer. Check the serial number on the electronic part and find a fitting replacement!

Does the Honeywell space heater shut off after a few seconds of running?

If your Honeywell space heater shuts off after turning it on, this can technically have only one explanation:

Something inside loads, charges or heats up, which takes time. Then, once this part reaches a certain threshold, the heater shuts off on its own.

Here are the possible reasons, with the likeliest first:

Clean dusty internal components

When your Honeywell space heater is filled with dust internally, it’s just a matter of time until it overheats.

When you turn on your heater, it works just fine. But after a few seconds or minutes, it stops blowing hot air.

The dust insulates the heater and accumulates a lot of heat. It’s like running your heater while it’s wrapped in a down blanket.

This can trigger the overheat protection and it can build up electric resistance in the circuitry, which can cause parts to fail.

So, open your heater and clean out all the dust that accumulated inside!

“Went and blew out the dust and dog hair and [my Honeywell space heater] works fine now!”

youtube comment

Technically, any other thing with a charging effect can cause a Honeywell space heater to shut off after some time.

The following two causes are rare and harder to fix. So, focus on cleaning your Honeywell space heater thoroughly before.

Check electronics for overcharged capacitors

Capacitors are electrical components that charge and discharge. If there is a fault in the electronic circuitry, it can cause a capacitor to overcharge. And once the voltage reaches a certain threshold, it causes your space heater to shut off.

Depending on the capacitor’s capacity and the input voltage, it might cut the heater off after a few seconds or after minutes.

To check for this issue you can open your Honeywell space heater’s case, and measure capacitor voltages on the circuit board.

There may be one capacitor where the voltage rises without stopping. Now, the issue is usually not the capacitor itself, but a part in its vicinity.

Visually inspect the circuit board for burn marks and broken pieces.

If you find a broken part, replace it using your soldering skills.

Check for a mechanical defect

Technically, even mechanical issues can have these charging effects, where the failure takes time to show up.

This is the case when parts change their shape due to heat or other forces.

For example, it might be that broken bearings in your heater’s fan work fine as long as they are cold.

But once they heat up above a certain temperature, they deform and block the fan’s rotational movement.

Such mechanical defects are rare. So, again, focus on checking the dust and the capacitors in your heater before you check for other mechanical defects.

To fix a mechanical defect, find out where it comes from. Usually, these defects make a noise, so they are simple to locate.

Then, replace the defective part.

What if you can’t fix your Honeywell heater?

The issues and fixes covered in this article cover all common space heater issues. In case you can’t find a solution for your specific issue, or you can’t perform the fix (because you need a soldering iron and electronic skills), here’s my philosophy:

Buy yourself the relief of a new space heater.

Don’t worry about fixing your broken heater if you don’t have the time or the knowledge to do it.

I personally recommend getting this DeLonghi oil-filled radiator (click here to view it on amazon) over another Honeywell heater.

The biggest difference is that oil-filled radiators have a heating element fully embedded in an oil-filled metal body.

So, the oil always wicks away heat from the heating element.

Oil-filled radiators, therefore, have no overheating effects. And you never have to deal with overheat-related repairs, such as deformed parts or triggered overheat protection.

Meanwhile, instead of trying to repair your Honeywell heater, you can sell it online (labeled as defective of course).

Many people fix and flip products as a hobby. So, selling your broken heater frees you from the burden of fixing it and you make someone else a small profit. It’s a win-win situation!