Electric shower hot...then cold...then hot

[mshafto]

My electric shower has recently started acting up.

It starts off fine - both heat and pressure.
Then there is a soft click or pop from within the unit
And the water goes cold suddenly.
Then it heats back up again.

Then a few minutes later, another click and I dodge the cold water again!

This problem doesn't happen during every shower, but its definitely happened more than once.

Any ideas?

 

[MarkBarl]

Sounds like a safety cut out on the element. Keeps the water flowing so you have power to the system. If you live in a hard water area, it is likely that the element has be come scaled. I believe that most are not changeable.

 

[ban-all-sheds]

I think that heater cans are often/sometimes available as spares (try http://www.showerdoc.co.uk/ ), but whether it makes financial sense to replace them IHNI...

 

[partpdoctor]

hi there,
you are probably running the shower too hot-ie the flow is too slow.
the clicking off and on of the thermal cutout is quite normal in these circumstances.
you dont have to turn the knob too far to have it plenty hot and not cycling on the thermal....

 

[Roflcopter]

This started happening to our shower last year, gradually getting worse. I thought it was going to be a new shower job, but I took the shower head off and found that it was full of crap that had built up over a period of time and was restricting the flow. Giving the head a good flush through completely resolved the problem.

Chris.

 

[uselessFCUK]

What happens with electric showers if the mains water pressure drops... I mean do these units have pressure switches to switch off the element during pressure drops?

If so, perhaps the water inlet mesh is clogging.

Is there an in-line non-return valve in the water feed to the shower?

Has any plumbing work been carried out recently?

 

[plugwash]

this could be caused by too low mains pressure but if it has started recently it is more likely something furred or clogged up.

Afaict the cutting out is a response to the overheating caused by insufficiant water flow.

 

[mshafto]

Thanks very much everyone for the suggestions.

I tried the *free* and *easy* solution first and cleaned out the handset.

It didn't seem clogged, but i must say I enjoyed much better water pressure this morning and I am cautiously optimistic that the problem is solved

No plumbing works lately or water pressure changes in my building, but i am in a very hard water area, so I'm thinking that's to blame.

 

[ban-all-sheds]

You'll also be getting furring inside the heater can - you've probably got a combination of causes, that and the handset. Cleaning the handset is just postponing the inevitable. If you can live without the shower for a few days, and if you can turn off the water supply to it, you could dismantle it, remove the can, (fill it with descaler, leave, rinse) x a few times. They are no more irrecoverable than a kettle, but it's time consuming and fiddly.

Check out the cost of a new one, and decide. Maybe you could replace the old one, and then descale the old one at your leisure to keep as a spare.

 

[SeanT]

When you fit a new shower, fit an inline descaler too.

 

[ban-all-sheds]

Do they actually work?

 

[SeanT]

Old man seems to think so, he's a heating engineer by trade, so I'll go with that - I think they are at least worth trying for the money - can't hurt can it.... A water softener is a proper solution (old man has one in his house) but it's £££ compared to an inline magnetic thing.

 

[Steve]

Someone fitted a new water heater at one of our shops. When they took the old heater apart, they found a lot of scale in it, and this was the reason for failure. They then arranged a second site visit to install a "magnetic"?? softener in the mains supply pipe. Nice of them. They must work.

(OOI, Never known this happen before. A company booking a second visit, or determining the cause of failure. Its normally "oh its broke, we'll fit a new one, toss the old one in YOUR SKIP")