Replacing a damaged electric shower unit

I have recently replaced a faulty Mira electric shower unit (8Kw / 8.5Kw) with a Gainsborough 9.5Kw shower unit. This worked Ok for approximately 5 months, then stopped heating up the water. Gainsborough replaced the "engine" of the shower. When this was fitted this shower worked Ok for approx. 3 weeks before the same fault occurred. Gainsborough stated that it is unlikely to be the unit and that the water pressure should be checked. The local water authority checked the water pressure outside , inside and at the shower and confirmed that there was enough water pressure to operate the shower. Gainsborough have sent out another "engine". This has been fitted but has not produced any hot water at all.
The original shower was fitted (approx. 5 years ago) by a qualified electrician. The cable is fitted to its own consumer unit with a 40a circuit breaker. I am not sure what size cable is fitted.
Can anybody advise on this problem?

If you have a multimeter or at least some form of voltage detector (NOT a neon screwdriver, please) then it would be worth checking that there is indeed a supply at the shower.

To do this, you would need to isolate the breaker for said circuit, remove the shower cover, check for any obvious loose wiring etc, then flip the breaker back on and check voltage between L-N and L-E.

If you have a supply there, it may be worth repeating the tests with the heating element running to ensure there is no excessive volt drop due to a loose connection or similar. However, you would need to exercise extreme caution - water, exposed live electrical connections, etc.

If the fault is indeed electrical, my money is on a loose connection either in the shower, shower isolation switch or in the CU which is causing the heating elements to die early.

Hi there

This is probably water pressure being too low. Can you measure it at the shower head?

Martin

martinxxxxxx said:

This is probably water pressure being too low. Can you measure it at the shower head?

Click to expand...

Read the OP again.

My moneys on a burnt neutral at the switch. Which should have been checked first. Gainsborough engineers should be wise to this common fault.

Point taken