Tumble Dryer Tripping The Electrics

What's happening?

Look at which switch goes off, because it tells you the kind of fault. If the RCD (the switch with a T or Test button) trips, current is leaking to earth. In dryers that is usually a heating element whose insulation has broken down, a motor or wiring fault, or water from a condenser or heat pump model reaching live parts. If a circuit breaker (MCB) or a plug fuse goes, the dryer is drawing too much current: a short in the element or motor, or the dryer sharing an overloaded circuit or extension lead. A dryer that simply stops mid-cycle while the house stays powered is usually its own thermal cut-out after overheating, often from lint build-up, which is a different problem. Condenser and vented dryers trip for the same reasons; condenser models add the water tank and pump as extra sources of leakage.

What usually causes it?

• A heating element with failed insulation leaking current to earth
• Water from a condenser box, pump or heat pump unit reaching electrical parts
• A motor, door switch or internal wiring fault
• A damaged plug, flex or socket, or a dryer run through an extension lead
• Too many high-power appliances on the same circuit at once
• A fault in the fixed wiring or socket if other appliances trip there too

Is it dangerous?

Treat it as a fault that needs fixing, not something to reset and carry on. Fire services publish specific tumble dryer safety advice, and Electrical Safety First advises cleaning the lint filter after every use and not running a dryer overnight or when you are out. A dryer that trips the RCD is leaking current where it should not, and repeatedly resetting it risks a shock or fire. If the dryer smells of burning, smokes or feels hot on the outside, unplug it and keep it closed.

Can I fix it myself?

1. Unplug the dryer and reset the RCD or breaker. 2. Leave the dryer unplugged and check the rest of the house stays on. If it trips with the dryer unplugged, the dryer is not the cause: call an electrician. 3. If the house stays on with the dryer unplugged, treat the dryer as the fault and do not run it again to test it. Never plug it into an extension lead. 4. Clean the lint filter and around the door seal, and on condenser models empty the water container and clean the condenser unit as the manual shows. 5. Check the model against the Electrical Safety First recall list. If it still trips, stop using it and book an appliance repair engineer. Do not remove the back panel with it plugged in.

When should you call an electrician?

Call an electrician if the trip happens with the dryer unplugged, if other appliances trip the same socket or circuit, if the socket or plug is scorched or hot, or if the RCD will not reset. If the trip only happens when the dryer runs, the dryer itself needs an appliance repair engineer or replacing.

What will the electrician actually do?

• Confirm whether the fault is in the dryer or in the fixed wiring
• Test the socket and circuit for earth leakage, polarity and insulation resistance
• Check the plug, fuse and socket for heat damage and replace as needed
• Check the RCD trips correctly and within time
• Advise whether a dedicated circuit or socket would suit the laundry area
• Recommend an appliance repair or replacement if the dryer is leaking to earth

Questions people ask

Sources & References

1. Electrical Safety First: Tumble dryer safety
2. West Yorkshire Fire and Rescue Service: Tumble dryers
3. Electrical Safety First: Product recalls
4. Electrical Safety First: Your questions answered (If my RCD keeps tripping)