Electric Shower Not Working? Here's What's Usually Wrong

Three different symptoms, three different causes. If the shower is completely dead, the problem is almost always the supply, the pull-cord switch or a tripped breaker. If it runs but only cold, the heating element or a thermal cut-out has usually gone. If it works then cuts out a few minutes in, that is a thermal cut-out doing its job, and something is making it operate.

Work out which of those three you have and you are most of the way to knowing what it will take to fix. Here is how each one plays out.

Before anything else

Switch the shower off at the pull cord, then off at the consumer unit. Electric showers are one of the highest-current circuits in a house and they live in the wettest room. Do not take the cover off. There are live terminals behind it carrying enough current to kill, and on most units the cover screws are the only thing between you and them.

Everything below is either something you can check without opening anything, or something to hand over.

Symptom one: completely dead

No lights, no noise, nothing when you pull the cord.

Check the breaker first

Go to the consumer unit and look for a switch that has flipped down, or an RCD that has tripped and taken a group of circuits with it. If the shower breaker has tripped, that is information rather than the fault. Something caused it.

You can reset it once. If it holds and the shower runs normally, keep an eye on it. If it trips again straight away, or trips the moment you turn the shower on, stop resetting it and call someone. Our guide to why a fuse box keeps tripping explains what repeated tripping is telling you, and what an RCD is covers the difference between an RCD trip and an overload.

Then suspect the pull cord

This is the one most people never think of, and it is genuinely common. That ceiling pull-cord switch is carrying 40 amps or more every time you shower. Over years, the contacts inside arc, pit and eventually burn out. The cord still clicks. Nothing happens.

Signs it is the switch: a faint burning or fishy smell near the ceiling rose, brown discolouration on the plastic, a click that sounds different from how it used to, or a shower that works if you jiggle the cord. Any smell of burning is a stop-now-and-call situation. We have written about what a burning smell from an electrical accessory means, and the same logic applies here.

Replacing a 45A pull-cord switch is a small job for an electrician and a genuinely dangerous one to attempt yourself in a bathroom.

Less often, the supply itself

A connection that has worked loose at the consumer unit, at the switch, or at the shower terminal block. Loose connections heat up, and heat makes them looser. This is the failure mode that starts fires, which is why a shower that has been intermittent for weeks deserves attention rather than patience.

Symptom two: running, but cold

The shower turns on, water comes out, the unit is clearly getting power. It just will not heat.

Usually this is the heating element. They fail with age, and hard water shortens their life considerably, which matters across most of London. When an element goes, you get flow but no heat, and often no other warning beforehand.

Second possibility is the thermal cut-out. Every electric shower has one, a safety device that isolates the heating circuit if the water gets too hot. Some reset themselves when things cool, some latch off until reset manually, and some are one-shot devices that have to be replaced. A shower that runs cold permanently after once running scalding hot points here.

Third, and the cheapest outcome, is that the unit has been knocked onto a cold or eco setting, or a temperature dial has been turned down. Worth ruling out before you call anyone.

Element and thermal cut-out replacement is possible on some models and uneconomic on others. Once a shower is past roughly ten years old, parts availability gets thin and the sensible route is usually a new unit. If yours is being replaced, our guide to what an electric shower installation involves covers what to check before you buy.

Symptom three: hot, then cold, then cuts out

This one is nearly always the thermal cut-out operating, and the interesting question is why.

• Low water flow. A blocked shower head or a clogged inlet filter means less water passing over the element, so the water heats too fast and the cut-out trips. Descaling the head is the first thing to try and it fixes this more often than you would expect.
• Falling mains pressure. If it only happens when someone runs a tap or the washing machine fills, that is a flow problem, not an electrical one.
• Scale on the element. Scale insulates the element from the water, so the element runs hotter than it should. Common in hard-water areas.
• A failing cut-out. Sometimes the device itself is tired and operating early.

If descaling the head and the filter does not resolve it, the unit needs looking at.

What you can safely check yourself

• The consumer unit. Look for a tripped breaker or RCD. Reset once, no more.
• The temperature and power settings on the unit. Sounds obvious. Gets missed.
• The shower head. Unscrew it, soak it in descaler, refit.
• Whether other things on the same RCD went off too. That narrows the fault down considerably and is genuinely useful information when you ring us.

What you should not do: take the shower cover off, replace the pull-cord switch, or open the consumer unit beyond resetting a breaker.

What it usually costs to put right

We will not quote figures blind, but as a rough guide the jobs sort into three tiers. A pull-cord switch replacement is at the small end. A new shower unit onto a sound existing circuit is a half day. A new unit that also needs a new circuit or a consumer unit with a spare way is the bigger job, and that is the one worth getting seen before you commit.

What we will do is diagnose the fault first and tell you which tier you are in before any work starts. Chasing symptoms is how people end up buying a new shower to fix a burnt-out switch.

Frequently asked questions

Why has my electric shower suddenly stopped working?

A sudden total failure is most often a tripped breaker, a failed pull-cord switch or a failed element. If it stopped mid-shower and the bathroom light is fine, start at the consumer unit. If nothing tripped, the pull cord is the next suspect.

Why is my electric shower running cold?

Flow but no heat almost always means the heating element has failed or a thermal cut-out has operated. Both are inside the unit and both need an electrician. Check the temperature setting first, since that costs nothing to rule out.

Can I replace an electric shower myself?

No. It is a high-current appliance in a room containing a bath or shower, which makes it notifiable work under Part P in England, and it has to be tested and certified. Our guide to Part P and building regs sign-off explains what that covers.

Why does my shower trip the RCD?

Usually moisture or degradation inside the unit letting a small current leak to earth, which is exactly what an RCD is designed to catch. A failing element is a common cause. It is a real fault, not a nuisance trip, and repeatedly resetting it is not the answer.

How long should an electric shower last?

Somewhere around eight to twelve years for most units in normal use, less in hard water and less again if the flow rate is marginal. Once you are replacing a second component on an older unit, a new shower is usually the better spend.

My shower works but the pull cord smells odd. Is that urgent?

Yes. A burning, hot-plastic or fishy smell at the pull-cord switch means the contacts are arcing and overheating. Turn the circuit off at the consumer unit and leave it off until it has been looked at. This is the failure mode that causes ceiling fires.

Shower dead, cold or cutting out and you want it diagnosed rather than guessed at? See our electrical fault finding and repairs, or if there is a burning smell call us now on 020 3653 2600 and we will get someone out. Same-day emergency callouts across every London borough.