RCD Keeps Tripping Repeatedly? Here’s Why

An RCD, or residual current device, is an important electrical safety device designed to prevent severe electric shocks and potential fires.

It is there to protect you and can be a lifesaver, but it can be very frustrating if your RCD keeps tripping. Repeated tripping generally indicates an electrical fault or safety issue and it’s important to deal with the issue.

In this article, we will look at some common reasons why an RCD switch keeps tripping and what homeowners should do next…

What Is an RCD?

A residual current device (RCD) is a sensitive safety device that automatically monitors and instantly shuts off electrical current in the case of a fault. If it detects electricity flowing where it shouldn’t – such as through a person who has touched a live wire – it will very quickly shut off. This can help reduce the risk of death, serious injury and fire.

In a domestic setting, RCDs are generally located in the consumer unit, commonly known as the fuse box. It works alongside but is different from miniature circuit breakers (MCBs), which protect individual circuits from overloading.

Common Reasons an RCD Keeps Tripping

If you’re asking the question, ‘Why does my RCD keep tripping?’, there could be a number of different reasons.

Some common reasons for an RCD tripping repeatedly could include:

Faulty Electrical Appliances

This could include small portable appliances such as kettles or toasters, or larger ‘white goods’ appliances such as fridges or washing machines. A tripping RCD could be triggered by an issue such as water ingress or an internal fault in the appliance itself. If you believe there may be a faulty appliance tripping electrics, you should safely unplug all appliances one by one.

Damaged Wiring

Old or deteriorated wiring, rodent damage and loose connections can all provide electrical current with a route to earth, which can be potentially dangerous and could also cause RCDs to trip.

Moisture or Water Exposure

Outdoor sockets and circuits can be prone to water exposure, but faulty appliances such as washing machines and dishwashers, and internal leaks can also expose electrical systems to moisture.

Overloaded Circuits

Too many appliances running at once, extension leads and high-demand appliances can overload the circuit. This could result in the RCD and possibly MCB tripping.

Faulty RCD Unit

In some cases, the RCD unit itself may have developed a fault. This may be more likely in older, damaged or worn consumer units and RCDs.

How to Identify What’s Causing the Problem

If you find your consumer unit tripping repeatedly, you can call an electrician immediately. The problem may be relatively simple to deal with though, especially if it is an appliance causing the problem.

Here’s what to do if your RCD and power keeps tripping:

1. Find your consumer unit and the RCD switch. If it is in the downward position, it is ‘OFF’ and has likely been tripped.
2. Unplug all appliances one by one.
3. Reset the RCD by flipping the switch back up.
4. If the RCD stays on, an appliance is probably the cause. Plug appliances back in one by one. If the RCD trips when an appliance is plugged in, this is likely to be the faulty one.
5. If the RCD trips again when you try to reset it with appliances unplugged, there may be another cause.
6. Check for any obvious water ingress in outdoor sockets, light fittings, kitchens and other areas. An internal leak may be harder to identify though.

If you cannot easily identify an appliance or moisture that is causing the issue, it is usually best to call an electrician for tripping electrics.

It is also advisable to not repeatedly force-reset the switch if it keeps tripping and you cannot find the cause.

When to Call an Electrician

You should not attempt to fix a fault in the wiring yourself if you are not a qualified electrician.

In general you should contact qualified local electrical services if there are:

• Frequent instances of unexplained tripping
• Burning smells or buzzing sounds
• Loss of power to multiple circuits
• Signs of damaged wiring

Professional electricians will be able to offer an electrical fault-finding service to allow you to identify and rectify the issues safely.

Can an RCD Trip Without a Fault?

It is possible for an RCD to trip occasionally or repeatedly without there actually being a serious fault in the electrical system. Overly sensitive devices and older systems may occasionally trip due to cumulative, low-level leakage from multiple appliances, rather than from a single dangerous fault. This is sometimes known as ‘nuisance tripping’.

The RCD itself may also develop a fault. If an electrician is unable to trace a fault back to another source, the RCD may be to blame and may need to be repaired or replaced.

As regulatory body NICEIC points out, it is absolutely essential to hire a registered electrician to carry out any work relating to the installation, replacement or repair of a consumer unit, including faulty RCDs.

Preventing Future RCD Trips

There are a number of things you can do to minimise the risks of RCD trips in the future.

Prevention is always better than cure, and regular electrical inspection services can help you to identify any potential issues – often before they become a problem and start tripping out RCDs.

You should avoid overloading sockets with too many extension leads or multi-way adaptors. High power devices such as washing machines, dishwashers and even kettles should ideally be plugged directly into their own wall sockets. You should also replace any damaged appliances.

If you have an older consumer unit, it might be worth getting it checked out and replace it if necessary.

RCDs are essential for electrical safety in the home, but they can be frustrating if they start to trip out repeatedly. A faulty appliance can often be identified but in many cases it is best to seek out professional advice in safely finding and rectifying fault.