One of the most common problems that you will see when you have a tumble dryer is that it will not dry your clothes. However, as you may have seen in our “heating but not drying” article, there are only three main functions to any tumble dryer.
That makes it very easy to determine the problem when you know which of the three it is not doing.
If you have a tumble dryer that, when you switch it on, it turns, you can feel air coming out of the exhaust, but it is cold air, and your clothes stay cold, you know that it is a heating problem. That fault is a pretty common one, and it is usually pretty easy to solve, too. While this article is based around a Whirlpool dryer, almost all tumble dryers have the same basic components to the heating system. We will go through those and tell you how to check them.
Table of contents
Tumble Dryer Not Heating Up
As I have said, the simplicity of a tumble dryer makes it easy to see what the problem is when it does not heat up. You will typically have three components in the heating system:
Here you can see the main three components:
- Overload reset switch. – There may be a heating fuse instead, but the newer models usually have an overload switch.
- Thermostat (bi-metal switch). The thermostat in this dryer is a bimetal switch. Some dryers will have a thermostat. However, that is only usually on dryers that have more than two heat settings.
- Heating element. – Again, these can look different, but they will often be spread out to allow the heat to dissipate.
The absolute first thing that you need to do before finding out why your dryer is not heating is to disconnect it from the mains supply and leave it for the electronics (capacitors) to discharge. 30 minutes or so should be ok.
Checking Your Tumble Dryer Components
When you are confident that your dryer component has discharged any remaining electricity, you will need to pull it away from the wall to get to the overload switch. They usually have access to them from the outside, so there is rarely a need to take any covers off yet.
Number 1 in the image above is the overload switch. It looks like this from the outside:
Here, the button is still depressed. When they have been activated, they often sick out more than in the image. But that will depend on your dryer and the style of switch that they used. Try to press it. If it slicks, it has likely tripped. That can be because you have used the dryer for a long time after the clothes are dry, or the fan is not turning. However, the drum (where you put the clothes) and the fan are often connected. Therefore, you would see that the drum is not turning, and that would be your issue.
If it doesn’t click, then it hasn’t overloaded, which means that your issue is with either parts 2 or 3.
Internal Parts To Check
You may need to remove more panels than me. Be careful when you do, as a lot of them have wires connected to the panels to keep them out of the way of moving parts. If you need to disconnect them, you should write notes about the wire placements, or better still, take photos. That will ensure that you put them back in the correct way when you need to.
When you have removed the panels, do a good visual check of all of the components. If you see any wires or connections that are black, you will need to change them as they are probably burnt due to poor connections. While that can be common due to the movements of the dryer, they are usually designed to cope with those vibrations well. Therefore, you are likely to find one of the next three faults more than burned connections.
If you have a fuse instead of an overload button, you can usually tell if it has blown, for the same reasons as above, quite easily. They are often black after they have blown. If the fuse is not black, or you cannot see the element, you may need to check it with a multimeter or replace it if you do not have one.
The common problem with a fuse is that it can be on the inside of the tumble dryer. For that, you will need to remove the covers. For the dryer that I am using to explain, I only needed to remove the back panel.
If you have a multimeter but do not know how to check a fuse, you need to take the fuse out of the holder as carefully as possible.
Next, turn your meter dial to the diode tester, that is the bottom option on my meter, as you can see in the next image.
The image on the left shows a blown fuse. That is because there are no numbers other than that which is visible when you are not connected to anything. That may be OL on your meter.
The image on the right is showing that the fuse is ok as there is a number other than OL or what is shown without any connections. Most meters will also beep to show continuity between the red and black probes of the meter.
Of course, if the fuse is blown, you will need to replace it. Make sure that you have another spare, as there is usually another reason why that fuse has blown. Although, as I said, it could be an overload fuse meaning that you have only run it for too long with no clothes.
Thermostat or Bi-metal Switch
Checking the bi-metal switch is the same as a fuse. Remember to take the wires off it first though. If there is no continuity (no beep or numbers), then you will likely need to replace the switch. The numbers will differ depending on the model of your tumble dryer and the components they used. If there is some continuity, then it is likely to be ok.
Remember that some tumble dryers will use a thermostat, it is likely to be in the same place, and the readings should be the same, providing it is cold (room temperature).
This component is likely to be cheaper to replace than the heating element, so if you have any doubt, you may want to buy one with a good returns policy and replace it to check.
Check the heating element in the same way as the last two components. However, you will need to do another check, which we will go into in a minute.
Again, remember to disconnect and check all of the wires for signs of burning or damage. If there are no signs, then you are ok to continue the check of the heating element.
Take your time to inspect the element for any cracks or damage. If there is any damage to the element, you will want to replace it, even if you have found that the thermostat was the problem. If you do not change a cracked element, you will be taking the tumble dryer apart again sooner than you would like.
The second check that you need to do on the element is a resistance check. Don’t worry, it is as simple as the other continuity checks, but you will be looking for different numbers.
Turn your multimeter dial to the lowest ohm Ω setting. The lowest on my meter in the images above is 200, but yours maybe 100, 250, etc. For this next step, we will go back to the image of my heater elements:
Here you can see that there are two element coils. I have marked the terminals 1&4, and 2&3. You will need to check them individually, ensuring that you check one coil at a time. If you check across two coils, you will get a false reading.
The ideal range for resistance in one coil is 10-50 Ω (ohms). If you have much more or less than that number, you will need to replace your coil. Sometimes, if you have more than one coil, it is best to replace them both at the same time. That is because, if you have one of the two failing, the second is probably the same age, and it has gone rough the same number of heat cycles. Therefore, it is likely to fail soon.
Tumble Dryer Not Heating – Conclusion
After you have checked and replaced the broken components, you should put the tumble dryer back together again, taking care to ensure that the wires are routed in the same way as they were to avoid any further issues with short-circuits or wires fouling on moving parts.
Check the dryer heats up with no clothes in by turning it on and feeling the vent air. It should heat up pretty quickly. If it does, congratulations, you have fixed your tumble dryer that doesn’t heat up. If it doesn’t, then you may need to replace a board or other component. However, that is rare, and you may need to get someone professional to look at it.