Persistent problem with thermostatic shower

Hello,

I have an exposed thermostatic shower mixer which has been cycling hot and cold, I was told to replace the shower but the new one has the same issue.

The shower isgoes cold and hot after several minutes of working fine, and then starts to cycle. The previous shower worked fine for 8 years before the problem started, the combi boiler, also 8 years old and otherwise working fine, has been checked and the shower valves have been checked for debris.

I am at a loss to what or where the problem lies. It’s a flat and the water pressure is low as is the flow rate and always has been, and I don’t believe this has changed recently but I can’t say for certain.

Any ideas?!

Thanks
Rita

Asked by Rita on 14th Aug 2026
No answers have been submitted yet
Find Tradespeople, compare up to 3 quotes!
It's FREE and there are no obligations
Ask a Trade
Got a question that only a tradesperson can answer? We have thousands of trades ready to answer any question you may have.
Ask your question
Ask a Trade

Are you looking for advice on a DIY project or have a question for our tradespeople?

We'll email your question to tradespeople who are skilled in your chosen category.

Your question will be made public - please do not include any personal details.

{{ first(ask.errors)[0] }}

By continuing you agree to the Community Guidelines.

Report Content

{{ first(reportForm.errors) }}

Thank you

Your report has been created and will be investigated shortly.

Ready to get a price for your home improvement project?
Get started

Over 1 million homeowners and over 50,000 tradespeople
use MyJobQuote nationwide each year