# Why your hair dryer trips the electrics

Source: https://blowandbarrel.co.uk/blog/hair-dryer-tripping-electrics
Published: 2026-10-11
Publisher: Blow and Barrel

**In short:** A hair dryer trips the electrics for one of two reasons. If the RCD trips, current is leaking where it should not, often from moisture or a fault in the dryer. If a breaker (MCB) trips, the circuit is overloaded, often because the dryer shares a socket or lead with other high-power appliances. A 2000 W dryer draws about 8.7 A on UK 230 V mains. If the dryer trips on every socket, stop using it.

When the lights go out the moment you switch on your hair dryer, the problem could be the dryer, the circuit or the way the two meet. UK homes have two kinds of protective device in the consumer unit, and which one trips tells you a lot. This guide explains RCD trips and breaker trips, shows the current a typical dryer draws, flags the extension lead trap and makes clear which faults are for a qualified electrician.

## RCD or breaker: which one tripped?

Open your consumer unit, sometimes called the fuse box, and look at which switch has dropped. Most modern UK consumer units have one or more RCDs (residual current devices), often marked with a test button, and a row of smaller MCBs (miniature circuit breakers), one for each circuit. Some homes have RCBOs, which combine both jobs for a single circuit.

An RCD trips when it detects current leaking to earth, for example through damp, damaged insulation or a fault inside an appliance. An MCB trips when a circuit draws more current than it is rated for, or when there is a short circuit. The two point to different causes, so note which one dropped before you reset it.

| Device that trips | What it detects | Common hair dryer cause |
| --- | --- | --- |
| RCD | Current leaking to earth | Moisture, damaged cable or internal fault |
| MCB (breaker) | Overload or short circuit | Too many appliances on one circuit, or a short in the dryer |
| RCBO | Both, for one circuit | Either of the above |
| Plug fuse blows | Overcurrent in that appliance | Fault in the dryer or its cable |

What each device is telling you

## How much current a hair dryer draws

Current in amps is power in watts divided by voltage. UK mains is nominally 230 V, so a 2000 W dryer draws about 8.7 A on its highest setting, a 1,600 W dryer about 7 A and a 2,400 W dryer about 10.4 A. Each sits below the 13 A fuse in a standard UK plug, which is why a healthy dryer on its own should not overload a socket.

Problems start when the dryer shares a socket, an adaptor or a lead with something else that draws a lot of current. A straightener, a heater or a kettle on the same 4-way lead can push the total well past 13 A. Try the numbers for your own setup with our [amps at the socket tool](https://blowandbarrel.co.uk/tools/amps-at-the-socket), and see [hair dryer wattage explained](https://blowandbarrel.co.uk/blog/hair-dryer-wattage-explained) for what the watt figure means.

| Dryer power | Current drawn |
| --- | --- |
| 1,300 W | 5.7 A |
| 1,600 W | 7.0 A |
| 2,000 W | 8.7 A |
| 2,400 W | 10.4 A |

Approximate current on 230 V

## The extension lead trap

A 4-way extension lead is usually rated at 13 A in total, not 13 A per socket. Plug a 2,000 W dryer and a 2,000 W heater into the same lead and you are asking for over 17 A. The lead's own fuse may blow, the lead may overheat, or the circuit may trip if other loads are running too.

Plug a hair dryer straight into a wall socket where you can. Avoid daisy-chaining leads or using cheap plug-in adaptors, and never run a dryer from a lead that is still coiled on a reel, as coiled cable can get hot under a heavy load.

Note: If a socket, plug or lead feels hot, smells of burning or shows scorch marks, switch off and unplug it. Do not keep resetting a breaker or RCD that trips repeatedly. Wiring and consumer unit faults are a job for a qualified electrician.

## When the dryer itself is the fault

If the RCD trips the moment you switch on the dryer, and does so in sockets on different circuits, the dryer is the likely cause. Common culprits are moisture inside the body after use in a steamy bathroom, damaged insulation in the cable, or a failing heating element. Hair dryers are double insulated, so they have no earth wire, but internal faults can still cause leakage that an RCD will spot.

Stop using a dryer that trips the electrics. Do not open it. If it is under warranty, contact the maker; otherwise replace it. Our [best hair dryers in the UK](https://blowandbarrel.co.uk/best/best-hair-dryer-uk) guide is a good starting point, and our explainer on [why hair dryers have no earth wire](https://blowandbarrel.co.uk/blog/why-hair-dryers-have-no-earth-wire) covers the double insulation side.

## When it is the circuit, not the dryer

If the dryer works happily in other rooms but trips one particular socket, or several appliances trip the same circuit, the issue may be in the wiring. Old wiring, a damaged socket, a loose connection or an RCD that has become oversensitive can all be at fault, and none of them is a DIY job.

Book a qualified electrician, ideally one registered with a recognised scheme. They can test the circuit, the RCD and the sockets and tell you whether anything needs replacing.

1. Note which device tripped: RCD, MCB or RCBO.
2. Unplug everything on that circuit, then reset the device.
3. Plug the dryer directly into a wall socket on its own.
4. If it trips again, try a socket on another circuit.
5. Trips everywhere: stop using the dryer. Trips one circuit only: call an electrician.

## Frequently asked questions

**Why does my hair dryer trip the RCD?** An RCD trips when it detects current leaking to earth. With a hair dryer, moisture inside the body, a damaged cable or an internal fault are the usual causes. If it trips in every socket, stop using the dryer.

**Can a hair dryer overload a circuit?** On its own, a typical dryer draws well under 13 A on 230 V. Overloads happen when it shares a socket, lead or circuit with other high-power appliances such as heaters or kettles.

**Is it safe to keep resetting the breaker?** No. A device that trips repeatedly is warning you about a fault. Stop using the appliance involved and, if the cause is not obvious, call a qualified electrician.

**Can I use a hair dryer on an extension lead?** It is better plugged directly into the wall. If you must use a lead, make sure it is fully unwound, rated for the load and not shared with other high-power appliances.

## Buying guides on this topic

- https://blowandbarrel.co.uk/best/best-hair-dryer-uk
- https://blowandbarrel.co.uk/best/best-lightweight-hair-dryer
- https://blowandbarrel.co.uk/best/best-hair-dryer-under-300

## Sources

- [HSE: electrical safety](https://www.hse.gov.uk/electricity/)