Can a leaking shower pump be repaired, or does it need replacing?

It depends where the water is. Hoses and union washers are parts and are worth replacing. Water from the pump body or the weep hole between the motor and the pump head is the shaft seal, and at that point a replacement pump is the honest answer — the seal is not sold as a serviceable part on most domestic units.

Is a leaking shower pump dangerous?

Treat it as an electrical risk first. It is a mains-voltage motor with water around it, so isolate it at the spur or consumer unit before you investigate, and do not switch it on to test. If water has reached the electrical connections, leave it isolated until an electrician or plumber has seen it.

Why does my pump keep leaking after the hoses were replaced?

Usually because the vibration that killed the first set is still there. A pump that is not sitting on its own feet, or is coupled with rigid pipe instead of flexible hoses, keeps working its joints loose. The other possibility is that the original leak was the body seal and the hoses were replaced hopefully rather than diagnostically.

How long should a shower pump last?

Five to ten years is normal in London. Dry running after an airlock, scale, and a badly mounted pump all shorten it considerably.

My shower pump is leaking | Leak Fix London

Do this first

Kill the power before you touch anything. A shower pump is a 230V motor that is now sitting in water. Switch it off at the fused spur, or at the consumer unit if you cannot see a spur, and leave it off. Do not run the shower to see how bad it is.
Do not test it by switching it on. A pump that has lost water is often a pump that is now running dry, and thirty seconds of dry running will finish a seal that might otherwise have been repairable.
Isolate the water. Most installations have service valves on the inlet and outlet. If yours does not, the pump is fed from the cold water storage cistern in the loft and you will need to stop that instead.
Look at the ceiling below. Pumps live in airing cupboards and under baths, so the first sign is often a stain in the room underneath rather than water you can see at the pump.
Dry everything completely, then watch. A pump covered in water tells you nothing. A dry pump tells you exactly where the water comes back.

Telling the three failures apart

Once it is dry, the leak will restart in one of three places, and they are not equally serious.

The flexible hoses. The braided anti-vibration couplings on the inlet and outlet are the most common failure and the least serious. They perish, blister or split, usually near the crimp. They are a replaceable part.
The union nuts and washers. A weep from the joint itself is usually a tired fibre washer or a nut that vibration has slackened. Re-seating it with new washers fixes it.
The pump body. Water from the seam between the motor and the pump head, or from the small weep hole underneath, is the shaft seal. That is the end of the pump. It is not a repair, and a pump leaking there is also about to fail electrically.

Why it failed

Shower pumps are consumables. Most give five to ten years, and several things shorten that. Dry running, usually after an airlock or a cistern that ran empty, destroys the seal in seconds. Scale chews impellers in hard-water London. A pump bolted down hard, or stood on something other than its own anti-vibration feet, transmits its vibration into the pipework and works the union nuts loose over a couple of years.

The thing that is most often wrong on these installations

A domestic shower pump is designed to be fed from a cold water storage cistern, not from the incoming main. If somebody has plumbed a pump directly onto the rising main to boost a combi or a mains-fed system, that is not just a performance problem — pumping from the supply is restricted under the Water Supply (Water Fittings) Regulations 1999, and the water company has an interest in it. It is worth knowing before you replace like for like.

The other common mistake is head type. Positive head pumps need the cistern above the shower outlet; negative head pumps have the sensing needed to start without it. Fitting the wrong one gives you a pump that will not start reliably, then dry runs, then leaks.

When the water in the cupboard is not the pump

Before condemning it, rule out the things sharing the cupboard. A weeping immersion heater boss, a hot water cylinder that has started to seep at a seam, a cistern overflow discharging inside rather than out, or a compression joint on a pipe above the pump will all put water on the same floor. If the pump is dry on top and wet underneath, look up.

Frequently asked

Can a leaking shower pump be repaired, or does it need replacing?: It depends where the water is. Hoses and union washers are parts and are worth replacing. Water from the pump body or the weep hole between the motor and the pump head is the shaft seal, and at that point a replacement pump is the honest answer — the seal is not sold as a serviceable part on most domestic units.
Is a leaking shower pump dangerous?: Treat it as an electrical risk first. It is a mains-voltage motor with water around it, so isolate it at the spur or consumer unit before you investigate, and do not switch it on to test. If water has reached the electrical connections, leave it isolated until an electrician or plumber has seen it.
Why does my pump keep leaking after the hoses were replaced?: Usually because the vibration that killed the first set is still there. A pump that is not sitting on its own feet, or is coupled with rigid pipe instead of flexible hoses, keeps working its joints loose. The other possibility is that the original leak was the body seal and the hoses were replaced hopefully rather than diagnostically.
How long should a shower pump last?: Five to ten years is normal in London. Dry running after an airlock, scale, and a badly mounted pump all shorten it considerably.

No find, no fee · £150 per hour. The rate is fixed before we attend and does not rise for a difficult property, an awkward access or an evening visit. The total depends on how long the job takes; the rate cannot change.