Fuse Box Keeps Tripping?

What you can safely check first

Most trips come from one faulty appliance rather than the wiring. You can usually find it in a few minutes without touching anything inside the consumer unit.

1. Unplug everything on the circuit that tripped. Kettle, washing machine, dishwasher, tumble dryer, immersion heater, anything in the garage or shed, and any outdoor lighting.
2. Reset the switch once. Push it fully down, then firmly up. If it stays on, the fault is in something you unplugged.
3. Plug items back in one at a time, waiting a minute between each. The one that trips the switch again is the faulty one. Leave it unplugged.
4. If it trips again with everything unplugged, stop. The fault is in the fixed wiring or a fitting and needs testing with proper instruments. Leave that circuit off and call us.

Never tape, wedge or hold a switch in the on position. It is disconnecting the circuit because something is wrong.

Which switch tripped matters

A consumer unit has two kinds of protective device, and they trip for different reasons.

A single breaker trips

This is usually an overload or a short circuit: too much load on one circuit, a failed heating element, or a damaged cable. If it is always the same breaker, the problem is on that circuit.

The RCD trips

The RCD is the switch with a test button. It trips when it detects current leaking to earth, often through moisture, a damaged appliance lead or deteriorating insulation. An RCD that trips on and off, particularly in wet weather, usually points to an outdoor circuit or a damp fitting.

Why fuse boxes keep tripping

A faulty appliance

The most common cause by far. Heating elements fail from the inside, and kettles, washing machines, dishwashers, immersion heaters and tumble dryers all tend to go the same way. The trip often happens only on the heat cycle, when the element draws current.

Water in an outdoor or damp circuit

Garden lights, outside sockets, and shed and garage supplies. After heavy rain these are the first thing we check, because water tracking into a fitting causes exactly the intermittent tripping that is hardest to pin down indoors.

Too much on one circuit

A breaker that trips when several high-draw appliances run together is doing its job. This is common in older homes where a kitchen was fitted without the circuits being upgraded to match.

Damaged or ageing cable

A nail or screw through a cable, rodent damage in a loft, or insulation perished with age. This does not improve on its own and will not show up on a visual check. It needs insulation resistance testing.

An old or failing consumer unit

Older units develop worn contacts and weak breakers that trip under loads they should handle. Units installed before RCD protection became standard also give no protection against electric shock on most circuits.

Is it urgent, or can it wait?

How we find the fault

Guesswork wastes your time, so we test rather than assume. We isolate the affected circuit, disconnect it from the unit and measure insulation resistance. That tells us whether the fault is in the fixed wiring or in something plugged into it. From there we split the circuit and work towards the fault until it is found.

We carry the usual parts on the van, including breakers, RCDs, sockets, back boxes and cable, so many faults are repaired on the same visit. If a part is not standard, we tell you what it is and what it costs before ordering anything.

Replacing a consumer unit

Where the unit itself has failed, or is too old to repair sensibly, replacement is the right answer. A new unit brings the installation up to the current wiring regulations, including RCD protection on circuits that previously had none.

In England, replacing a consumer unit is notifiable work under Part P of the Building Regulations. It must be certified and notified to Building Control, either by an electrician registered with a competent person scheme or through your local authority. Since January 2016 the wiring regulations have also required consumer units in homes to be made of non-combustible material such as metal.

You should be given an Electrical Installation Certificate when the work is finished. Keep it, because you will need it when you sell or let the property.

What it costs

The cost depends on the fault. A failed appliance lead is a different job from a damaged cable under a floor or a consumer unit that needs replacing. You get a fixed price before any work starts, and there is no extra charge for nights, weekends or bank holidays. If we find something further once the cover is off, we tell you what it is and why before going ahead.

Where we cover

We cover 83 towns and cities across England. Tripping faults are among the jobs we are called to most often in these areas:

• Hemel Hempstead
• Ipswich
• Colchester
• Chester
• Exeter
• Reading
• Bournemouth
• Halifax

Not on the list? See every area we cover or call and we will confirm in seconds.