Electrics Keep Tripping? Causes, Checks and When to Call

What an RCD, an MCB and an RCBO each trip on

Look at the switches in your consumer unit and find the one that has moved. A tripped switch points down, in the off position. If every switch is still up and the whole house has lost power, nothing has tripped, and a house with no electricity is a different problem from a trip.

Each kind of switch trips on different faults, so the one that has moved tells you where to look first. An RCD cuts the power almost instantly if current leaks to earth, and RCDs are tested to trip within 30 milliseconds.

Switch	What makes it trip	Where to look first
RCD (residual current device)	Current leaking to earth	The appliances on the circuit
MCB (miniature circuit breaker)	An overload or a short circuit	How much is running on that circuit
RCBO	Earth leakage, an overload or a short circuit	The appliances and how much is running, on its own circuit

Why your electrics keep tripping

Each of these can trip the electrics, and a faulty appliance is the most common reason an RCD trips. A power surge can trip an RCD too.

Cause	What to know
A faulty appliance	Especially one with a heating element or a motor, such as a washing machine, oven, kettle, tumble dryer or dishwasher
A boiler fault	A problem with its internal wiring or pump, a failing component, or moisture
Moisture	In bathrooms and kitchens, in outdoor sockets and garden lighting after rain, and in garages and outbuildings
Several appliances on one circuit	Small earth leakages add up across them until the RCD trips, known as nuisance tripping
Damaged or ageing wiring	Including the wiring in homes built before the 1970s and never rewired
A faulty or over-sensitive RCD	It feels warm, looks discoloured or will not stay reset
An overloaded circuit	It trips an MCB, and the MCB trips again after you push it back up

Electrics tripping at night

When the RCD trips at night with nothing obviously switched on, think about what runs automatically, such as fridge and freezer motors, heating on a timer and garden lighting. Garden lighting that trips it after rain points to moisture, and a trip when the heating comes on can mean a boiler fault.

How to find what is tripping your electrics

If an MCB has tripped, push it back up. If it trips again, the circuit may be overloaded, so unplug some appliances or move them to another circuit, and if that does not stop it, call an electrician to check for faulty wiring.

For a tripped RCD, work through the checks below in order. They show whether the fault is in an appliance you can unplug or somewhere you cannot reach. If the RCD trips again at once and will not stay on, stop and call an electrician.

RCD tripping with nothing plugged in

If the RCD still trips with everything unplugged and the MCBs off, nothing you plugged in is causing it. The cause is the wiring, a fixed appliance or the RCD itself, and finding which one is a job for an electrician, so stop resetting it here.

When to call an electrician

Stop resetting and call a registered electrician when any of these apply:

• The RCD will not stay reset with everything unplugged
• There is a burning smell, scorch marks or sparks at the consumer unit
• It keeps tripping after the faulty appliance has been unplugged
• Moisture may have got into the wiring
• A boiler or another fixed appliance is involved, and a boiler fault may need a Gas Safe registered engineer as well
• The consumer unit or wiring is over 25 years old
• Bathroom or kitchen circuits have no RCD protection

Among the Nottingham electricians ranked on their registrations and guarantees, Urgent Electrical Services in the city centre is available 24/7 with a stated 60 to 90 minute response and no call-out fees, and Central Electrical Contractors on Carlton Road runs a 24-hour emergency call-out.

When you call, pass on what your checks found. The switch that tripped, when it trips, whether it holds with everything unplugged and the age of the consumer unit tell the electrician where to start.

What it costs to fix electrics that keep tripping

Checkatrade’s electrician rates put an electrician at around £50 an hour, usually £45 to £60, and emergency work at around £90 an hour, so an emergency hour costs nearly double a standard one.

An older fuse box with no RCD protection can get it from a separate RCD device or a consumer unit upgrade. Checkatrade prices a 10-way RCBO consumer unit at around £485 including installation, and the number of circuits and the type of board move the price of a new consumer unit up or down.

The type of board also decides how much one fault switches off. On an RCBO board each circuit has its own RCBO and is fully separate from the rest, while on a dual RCD board everyday circuits such as lights and sockets share an RCD, so one fault can switch off several areas of the home.

How to stop your electrics tripping again

Test the RCD every 3 months by pressing its test button. The power should cut, and if it does not, the RCD needs replacing by an electrician.

Then keep faults off the circuits in the first place:

• Do not overload circuits, especially in kitchens and home offices, or on extension leads
• Keep outdoor and bathroom fittings dry and sealed
• Have appliances serviced
• Avoid cheap devices that do not meet UK safety standards
• Have an electrical safety check every 5 to 10 years, or every 5 years in a rented home