Tumble Dryer Thermostats - All You Need To Know
Last Updated: 12 Jan 2016
If your tumble dryer works but there’s no heat then it could be a thermostat that has failed. To learn about other faults that can cause the same symptoms see our guide on 'why is my tumble dryer blowing cold air'.
What are tumble dryer thermostats
There are usually 2 types of thermostats found on the modern day tumble dryer, Thermal Overload Cut-Out (TOC) and the Heat Control Thermostat.
Thermal Overload Cut-out (TOC)
Manufacturers of tumble dryers have by law to ensure that overheat protection in the event that the normal heat control thermostat fails is fully maintained. This means that if your tumble dryer overheats for whatever reason the TOC will trip (break the heating circuit) and they should not automatically reset themselves. This will leave your tumble dryer working but unable to produce heat. There are a number of common reasons why TOC’s trip which we’ll look at in due course.
The most common TOC’s found on today’s tumble dryers are ‘One Shot Thermostats’ meaning that once it trips it cannot be re-set, and so needs replacing, and manual reset thermostats. One shot thermostats are normally located just above the heater element. Manual re-set thermostats are normally reset by the user by pressing a small red button often protruding from the rear panel of the tumble dryer.
Heat Control Thermostat
The heat control thermostat will often look exactly the same as the TOC with perhaps a distinguishing coloured spot to help identify the difference between the two. The TOC and Heat Control thermostat should be sold as a pair and it is important that you always replace both at the same time.
The heat control thermostat simply regulates the heat by continually opening and closing the electrical circuit to the heater element. So in the event of the heat control thermostat failing it will either fail ‘open’ which will mean there will be no heat, or ‘closed’ which will mean that the element will continue to heat until the temperature rises and trips the TOC.
How To Replace Tumble Dryer Thermostats
Hi, I’m Lee from Ransom Spares and I’m going to be showing you how to replace the thermostat’s on a tumble dryer. I’m going to demonstrate on this Creda dryer, however the procedure should be very similar no matter what make and model you have.
First of all remember to always unplug your tumble dryer from the mains before carrying out any repairs.
Thermostats are normally located at the rear of the machine just above the heater element.
So, we first need to remove the screws that are holding the heater element cover in place.
Now we can see the thermostats which are about the size of a 5 pence coin.
Make a note of how the wires are attached to the thermostats and remove them.
Now we can remove the screws that are holding the thermostats in place.
Where there are 2 fitted you should always replace both thermostats.
It’s worth checking out our online video to find out more about why your tumble dryer thermostats have blown.
So there you go that’s how you replace the thermostats on a tumble dryer. Thermostats and all other Tumble dryer spares can be found on the Ransom Spares website.
Why does the tumble dryer TOC keep tripping?
If your TOC has failed then there is a reason why. If it’s not just that the TOC itself is actually faulty then it will most likely be one of the following:
Opening Tumble Dryer Door Early
This is a common mistake that tumble dryer users make. At the end of the drying cycle there is normally a cooling down period where the heating element is turned off but the flow of air continues to be circulated around the dryer. This helps cool the heater element prior to the end of the cycle.
If the user opens the door before the end of the cycle then the heater element will remain hot because the air circulation has been stopped. This is likely to cause the temperature in the area where the heater element and TOC are located to rise and trip the TOC.
The best course of action if you want to end the drying cycle early is to check the clothes are dry, re-close the door, and turn the dial on to the cooling cycle for a few minutes. The cooling cycle is normally denoted as a propeller on the control dial.
Blocked tumble dryer filters are another cause of overheating. All that is happening in this scenario is that the circulation of air over the heater element is limited due to obstruction. It is recommended that you clean you tumble dryer lint filter after every use.
By Lee Gilbert