Shower Thermostat

[Arthur2]

Hi all. Sorry. Sort of a re-post here. If there are typical characteristics that a bar shower thermostat requires replacing, what are they ?

Thanks.

Arthur

[Harry Bloomfield]

Arthur2 presented the following explanation :

Not sure you mean by 'bar' shower?

For a basic shower.... Water flows and is heated by the element, water temperature is governed by the rate of water flowing - the faster the flow, the colder the output. The switching on of the element is by a flow pressure switch, no flow and this turns itself off. It addition there is a temperature switch, which turns of the element if the water temperature rises too high - which could occur if the water outlet is obstructed.

[Arthur2]

The shower has been running a bit hot since I descaled it about 6 weeks ago..in that, it was difficult to run it at less than what felt like 36 degrees. The symptons for its current failure are the same as before..shower runs ok for a minute then the flow reduces to a trickle..then nothing. Do these thermostats have a failsafe? e.g. If the thermostat is unable to keep the temp below a limit, will it shut itself off?

Arthur

[Harry Bloomfield]

on 26/08/2007, Arthur2 supposed :

The thermostat will cut in and out for safety - ensuring the temperature cannot rise above the stats set (none adjustable) temperature.

By your description it sounds as if you need to find out why the flow is poor through the shower - perhaps a washer breaking up or similar?

[Arthur2]

I replaced both washers when I descaled it. And as I said, the shower worked fairly well for 4 or 5 weeks.

Arthur

[Pete C]

Hi,

How did you descale it exactly?

Did it stop working all of a sudden or over a period of time?

cheers, Pete.

[Arthur2]

Very much, suddenly.

[Pete C]

Hi,

Only thing I can think of is either some debris like PTFE tape has blocked the cold inlet, or a lump of loose scale has got stuck in the valve.

With gradual scale buildup I'd expect it to have increasing trouble holding the set temperature,

cheers, Pete.

[Arthur2]

When I first installed it I was far too heavy with the wrenches and when I disassembled last month I saw that the filter washer was crushed and probably allowed who knows what.. perhaps even a piece of the filter washer mesh. I currently have the shower body disconnected from the inlets so I think I'll let the water through for a minute and watch if something is flushed out. If nothing shows I will have to send a photo of the thermostat to the showerdoctor.

Arthur

[Pete C]

There may be non return valves on the inlet, if so it'd be worth checking them.

It may also be possible to back-flush it by connecting the outlet to a hot/cold water supply, and holding any non return valves open.

cheers, Pete.