Why Is My Tumble Dryer Blowing Cold Air?

Posted by Ship It Appliances Ltd on 15th May 2017

Why Is My Tumble Dryer Blowing Cold Air?

If your tumble dryer is not heating up, it could be down to one of a few problems. While you can call an engineer to fix the problem, this can be expensive and may be unnecessary. Sometimes, you’ll be able to fix these problems yourself with nothing more than a replacement part and a bit of know how. We’ve put together a simple guide on how to detect the issues with your tumble dryer and what you can do to fix them.

One of the most common reasons your tumble dryer decides to blow out cold air instead of hot is, rather ironically, because it has overheated. Manufacturers have a legal requirement to ensure that when your dryer gets too hot there is some form of control in place to prevent it catching fire. This is where your thermal overload cut-out comes into play – it is designed to stop working if your dryer gets too hot.

In some models this should be easily fixable – some tumble dryers have reset buttons on the back of the machine so all you will need to do is hold in the button and wait for it to click.

If your tumble dryer does not have a reset button it is likely you will need to replace your thermostat and thermal overload cut-out (TOC).

What causes a tumble dryer to overheat?

There are various reasons a tumble dryer might fail, including:

  • The filter hasn’t been cleaned regularly enough. If you don’t clean the filters after use, dust will build up and block the air flow. The air flow draws in cool air to keep the temperature down when using the dryer. Blockages are a fire hazard but they will almost definitely cause your dryer to overheat and stop working. If your dryer doesn’t have a reset button, it won’t be as simple as cleaning it out after the fuse has tripped – you will need to replace its heating elements to get it working again.
  • Opening the door mid-cycle or too soon after the load has finished. After a spin, tumble dryers need a cooling down period. You should allow for this before opening the door. If you don’t leave your dryer for a few minutes before removing your laundry, you could trip the TOC. Don’t open the tumble dryer mid-way through the cycle or immediately after it stops; instead trust the timer and let the dryer cool down.
  • Overloading the dryer. If you put too much in the dryer it will block the airflow, again causing temperatures to rise and potentially overheat. There should be a maximum capacity mentioned in your user manual but general rule of thumb suggests your drum should be about half full. A common reason people overload their tumble dryer is a belief that multiple loads cost too much in electricity. This is actually a misconception – if you overload your dryer, your drum has to work twice as hard. This can actually cost more in electricity costs than doing multiple loads.

What is a thermostat and TOC?

The thermostat monitors the temperature of the tumble dryer. It is connected to a heater element and opens and controls the circuit, raising the temperature and cooling it down. The thermostat knows when to cool itself down so will close the circuit with the element once it starts getting too hot.

The TOC, or thermal overload cut-out, protects against overheating, so if your tumble dryer does get too hot, it will trip the circuit stopping the dryer heating. Sometimes this can be reset but more commonly both the stat and TOC will need to be replaced.

How do I replace the TOC and thermostat in my dryer?

First you should test to see whether there is a circuit between these and whether they have actually failed. No circuit is confirmation that the TOC has tripped. You can check this with a continuity test meter.

If you’re sure this is the reason for the fault, you will need to unplug your appliance and locate the thermostat. This should be located underneath the back panel of your dryer so you will need to remove the back of your dryer.

Both your thermostat and TOC are small round objects, they look like bottle tops, and will have wires attached to either side of them. They should also be screwed down onto the machine.

To replace them:

  1. Dislodge the wires and unscrew the faulty parts.
  2. Get your new replacement parts and screw in place of the old parts.
  3. Attach the wires to the metal arms on either side of the components. This is their connection to the heating element.
  4. Replace the back of your tumble dryer.

It is worth noting while most thermostats and TOCs are located under the back panel of the dryer, some can be located at the front. Reaching these can be quite tricky, so at this point it might be worth calling a professional. If ever in doubt don’t try and do this yourself. While the tasks is relatively straightforward, it does involve playing with electrics so if you’re ever unsure seek expert help or advice.

Need help? Call our team on 01623 625 658