Water leaking from the shower unitwhat to check
Water escaping from the casing rather than the head puts mains water inside a live appliance. Manufacturers say stop using it, and that is the right answer.
Take care
What this means
There is a distinction on this page that decides everything, and it is easy to make from outside. Water coming from a joint on the outside of the unit — the inlet connection, the outlet elbow, the hose where it screws on — is a plumbing leak on an appliance that happens to be electrical. Water coming from inside the casing, running down the wall from under the cover or dripping from the seam, is a different matter entirely, because it means mains water is inside an enclosure that contains the terminal block, the solenoid and the element connections. That is the case where the manufacturers stop giving remedies and start giving instructions.
Bristan put it in the safety section of both guides read for this category rather than in the troubleshooting table: do not operate the shower if water is leaking from the shower unit itself, and if it happens, turn off at the mains electrical supply. There is a third source that looks like a leak and is not one, and it is worth ruling out first because it is common and it means something specific.
Most electric showers have a pressure relief device — a deliberately weak part that bursts to protect the unit if the outlet blocks — and it vents through a small plastic tube or stub that points down out of the bottom of the case. Water from that is the shower having protected itself, not the shower leaking, and it has its own page because the answer is different: find the blockage first, then fit a new device. Telling the two apart is a matter of where the water comes from, and it is worth two minutes with a torch before you decide which problem you have.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Inlet or outlet connection loose or perished | The external joints and their washers. The commonest leak and the least serious, because the water never reaches the electrics. | Common |
| Hose or hose washer failed | A split at the hose tail sprays back against the unit and looks exactly like a casing leak until you look closely. | Common |
| Pressure relief device has vented | Water from the small stub under the case. Not a leak at all — the device has burst to protect the unit and needs the blockage found before it is replaced. | Occasional |
| Internal seal or heater tank failed | Water inside the casing, in with the terminal block and the element connections. This is the one that means stop using it. | Occasional |
| Scale damage to internal joints | In hard water areas scale works at the seals and unions inside the unit over years until one of them lets go. | Rare |
What to try yourself
Pull the cord and switch the shower off before investigating anything. Water and a 40 amp appliance is the combination this page exists for.
If water is running out of the casing rather than from a visible joint, leave the circuit off at the consumer unit and stop there. That is the manufacturers’ own instruction, not a precaution added here.Dry everything, then look with a torch for where the water actually starts. The three candidates are the inlet union, the outlet elbow and hose, and the small stub under the case.
If it comes from the small stub, this is a burst pressure relief device rather than a leak. Do not fit a new one until the blockage that burst it has been found.
If it comes from the hose or its washer, unscrew it, check the washer and the tail for splits, and replace the hose. Hoses are consumables and a new one is inexpensive.
If it comes from the inlet or outlet union, close the servicing valve, unscrew the joint and renew the washer. Snug rather than tight — these are plastic threads and they crack.
If you cannot find an external source, treat it as an internal leak: leave the circuit off and have the unit looked at rather than running it to see what happens.
Get a qualified electrician to look at your electric shower
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified electrician, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£200
Time on site
30 minutes
A hose or a washer is a few pounds. A pressure relief device plus finding what burst it is a small visit. An internal tank leak is normally a replacement unit rather than a repair.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related electric shower fault codes
- Pressure relief device has burstGet it checkedWater from the small tube under the shower means a one-shot safety part has ruptured. Replacing it without finding the blockage just bursts the next one.Related: leaking
- Shower runs coldGet it checkedWater flows but never heats. On an electric shower this is nearly always the supply, the flow through it, or an element that has stopped working.Related: same brand
- Shower keeps tripping the electricsStop — call an engineerA shower that trips the breaker or RCD is reporting a real electrical fault. Do not keep resetting it to get one more shower out of it.Related: same brand
- Shower completely deadGet it checkedNo neon, no water, nothing when you pull the cord. On an electric shower a total dead is almost always the supply rather than the appliance.Related: same brand
- Thermal cut-out has operatedGet it checkedThe safety device has taken the elements out of circuit. Whether you can reset it yourself depends entirely on the brand, and the answers differ.Related: same brand
- Water suddenly scaldingGet it checkedAn electric shower that runs too hot is usually short of flow rather than making too much heat. The exception is a thermostatic model, which should not do this at all.Related: same brand
Related guides
Common questions
It is only a slow drip. Does that change anything?
Not if it is coming from inside the casing. A slow drip into an enclosure with live terminals in it is the same fault as a fast one, and it is the reason both Bristan guides put this in the safety section rather than the troubleshooting table.
Water only appears when the shower is running. Where is it from?
Something pressurised, which points at the connections, the hose, or the pressure relief device rather than at a slow seep. It narrows it usefully — dry everything and run it for ten seconds with a torch on it.
Can a leaking shower be repaired or does it need replacing?
External joints, hoses and washers are straightforwardly repairable. A failed internal seal or a leaking heater tank usually is not worth it — the tank is most of the unit, and a shower that has been wet inside has had water where the electrics are.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.