Shower constantly overheating

[Peavy]

Hi, I wonder if anyone can offer me some advice.

I have a Bristan B85 shower which trips out thermally every couple of minutes. Water flow seems good, not slow or intermittent, and the water temperature is not getting unusually hot before it trips. Once it has tripped it runs cold for a few seconds and then re-sets itself and warms up again...

Do I just need to change the thermal cutout switch or could this be caused by something else?

Many thanks in advance.

Paul

 

[hazetimesfive]

my money would be as you said. not familiar with that model but you may be able to test the stat with a multimeter

 

[seco services]

B85 is just a newteam shower.
Do the reduce temp or low pressure neons light when this happens ?

You got a flow issue.

 

[Peavy]

Thanks for the replies. I get a "Reduce temperature" light but the "Low pressure" light does not come on.

I wasn't sure about getting a meter on to the thermal switch because I assumed it wouldn't be safe to run the shower with the cover off. I guess I can give that a go carefully.

 

[seco services]

Thanks for the replies. I get a "Reduce temperature" light but the "Low pressure" light does not come on.

That just tells me it's a tco issue not a pressure switch issue.

I wasn't sure about getting a meter on to the thermal switch because I assumed it wouldn't be safe to run the shower with the cover off. I guess I can give that a go carefully.

That's not how you test a tco.
Tco is tested with mains power off and you test them for continuity only.

Your tco is ok because the shower heats it's just cycling on the 1st stage of the tco, if it hits the 2nd stage it totally fails.

Run the shower with the head off, Then what do you get ?

 

[Peavy]

It does still cut out with the head off but it takes longer to get to that point. Thanks for the clarification on testing the TCO.