Tumble dryers are humble machines that we depend on to dry our clothes when the washing line isn’t available.
Like all kitchen appliances, tumble dryers are far from immune to problems, and after years of service, faults become more likely.
Luckily, many are pretty easy to solve!
This is a guide on what to do if your tumble dryer fails to heat up correctly.
Which type of tumble dryer do you have?
There are two types of tumble dryers: vented and condensing. Both work similarly but feature different components and mechanisms.
- If you have a vented dryer, it’ll have an air vent somewhere at the back. Most older dryers are vented. Vented dryers blow hot air across the clothes as they rotate in the drum.
- Condensing dryers don’t require venting. Instead, they use a condensation process to remove moisture from clothes. These tend to be more modern and can be installed in practically any room.
1: Heater fuse has tripped
The first possibility is that the internal thermal overload cut-out (TOC) has been triggered, preventing the dryer from heating up at all. If this is the case, modern tumble dryers will show an error message to this effect. For example, Beko dryers typically display fault code 14 when this happens, indicating that the internal fuse has tripped.
However, if the dryer doesn’t switch on, check the mains plug to see if the fuse has blown. This would indicate an electrical fault inside the dryer.
The internal fuse will trip if the dryer gets too hot, in which case there are a few possibilities:
- The ambient temperature is too hot or humid: Condensing dryers don’t like high ambient heat and humidity, making it harder for them to remove condensation from clothes. Vented dryers are also more likely to overheat when the ambient temperature is too high.
- The fluff filter is blocked: If the fluff filter is completely clogged, the tumble dryer is more likely to overheat. Modern dryers will likely display a code to prompt you to unclog the filter.
- Short circuit: Another short circuit or electrical fault in the machine can cause the internal cut-off to trip.
- Cycle interrupted: If you interrupt the dryer mid-cycle, the air cooling mechanism will stop prematurely. This may trigger/exacerbate overheating problems.
How to fix a tripped fuse
If the thermal fuse trips, let the dryer cool completely for around 30-minutes to 1 hour. Check the fluff filter and clean if necessary. Then, reset the dryer or switch it off and on to see if the problem persists.
2: Heating element may have malfunctioned
Both vented and condensing tumble dryers feature heating elements. If the heating element fails, the machine won’t heat up at all, but may still spin. Modern dryers should display an error code to indicate an issue with the element.
If your machine seems to be working but doesn’t heat up, reset it and try again. The element may have worn out/blown if it fails to heat up. This is pretty unlikely on newer dryers.
How to fix the heating element
The only way to fix the heating element is to replace it. This involves disassembling the dryer and checking each part to locate the fault. Only attempt this if you have electrical experience, as you’ll need to measure each component with a multimeter.
3: Exhaust vent may be full of lint
If you have a vented dryer, the exhaust can also become clogged with lint, dust and other debris. If this happens, the dryer may prevent itself from heating up.
How to fix the exhaust vent
Ensure the vent itself is clear, especially after periods of heavy use. The vent is typically mounted on the rear of the dryer but may not always be obvious if you’ve moved into a house or flat with a pre-installed dryer.
4: The thermostat may no longer work
Tumble dryers feature thermostats which tell the heating element when to heat up and to what temperature. If the thermostat fails, the dryer may stop heating up, not heat up enough, or cut out too often.
How to fix the thermostat
To fix the thermostat, you’ll need to open up the machine and correctly diagnose the fault. This involves testing electrical components with a multimeter to find the issue. Only attempt this if you have electrical experience.
5: Internal short circuit or electrical fault
Modern tumble dryers feature multiple components, and a fault with any could conceivably prevent the dryer from heating up.
Modern dryers often have error codes that indicate short circuits or issues with the internal circuit boards - be sure to check your manual if you see one.
An internal short circuit could also cause the dryer to blow fuses or repeatedly trip your home’s breakers every time you switch it on.
How to fix a short circuit
Fixing an internal short circuit is tricky and involves checking each component methodically using a multimeter. Only attempt this if you have electrical experience.
6: Condensing reservoir is full/blocked
This only applies to condensing dryers. Condensing dryers are either plumbed into the drain or feature a water reservoir that fills during use. If the reservoir is full, the dryer will likely tell you to empty it via a light or code on the panel.
Another possibility is that the reservoir is blocked by debris or sludge. Again, check the inlet/outlet for obstructions.
How to fix a blocked condensing reservoir
Occasionally, the internal plumbing to/from the reservoir will get blocked by dirt or sludge. Try running the dryer without any clothes, pouring warm water in each time and clearing the reservoir.
7: Faulty condensing pump
Condensing dryers use pumps to move the water from the drum into the reservoir. The pump can fail, which usually triggers an error code on the front of the dryer.
To diagnose this, run the dryer without clothes and pour some water into the drum to see if the dryer removes the water. If not, the pump may be faulty.
How to fix a faulty condensing pump
If the pump fails, it’ll need to be replaced. This requires disassembling the machine - do not attempt unless you have electrical experience.
For more tips on troubleshooting condensing dryers, check out this article.
8: Mechanical faults
Various mechanical faults inside the dryer can cause it to not heat up. For example, if there’s an issue with the drum, motor or rollers, then this will likely prevent the machine from heating up properly.
How to fix mechanical faults
It very much depends on the mechanical fault. If the dryer isn’t spinning, check out this article.
9: Moisture sensor dirty
Modern dryers have internal moisture sensors that auto-detect the moisture levels of clothes, enabling them to shut off when the clothes are dry.
If the moisture sensor gets dirty, it’ll fail to trigger. More rarely, the sensor will fail completely.
How to fix the moisture sensor
Consult your manual to locate the moisture sensor - it should be just inside the drum. Then, simply wipe clean with a wet cloth.
10: Faulty fan
Dryers feature fans that circulate the warm air inside the drum. If the fan fails, the dryer won’t be able to introduce and circulate air in the drum. Modern dryers will often display an error code if this is the case.
How to fix a faulty fan
A faulty dryer fan will need to be replaced. This involves disassembling the dryer and testing the components - don’t attempt without electrical experience.
How to prevent tumble dryer heating faults
Actively preventing faults by using your dryer properly is always the best course of action!
Here’s a few things to bear in mind:
- First and foremost, always use your dryer as per what the manual recommends. If you constantly overload it or cut it out mid-cycle, you’ll increase the likelihood of faults.
- Moreover, installing a dryer in a small, warm and humid room increases the chance of overheating, regardless of whether you have a vented or condensing dryer.
- Another crucial point is to plug your dryer into its mains socket, not an extension lead. Dryers draw a lot of power and shouldn’t be combined with other electrical appliances.
- Clean the fluff filter regularly. Most modern dryers will tell you when this is necessary; otherwise, it’s essential to check regularly.
- If you have a condensing dryer, empty the reservoir on a regular basis.
When to call an expert
Generally speaking, it’s sensible to call an electrician or repairer for any fault that requires you to disassemble the machine. In the event of electrical faults, it’s necessary to work through the dryer components methodically, testing them sequentially with a multimeter.
If basic fixes and troubleshooting fail or the error code indicates a serious fault, it’s time to call for expert help.
Most fixes are inexpensive - especially compared to the price of a new dryer!