Boiler or Thermostatic shower valve problem?

[BONZO-84]

Hi,

Long-time reader and extremely grateful for help in fixing dishwasher and washing machines over the years, I don’t post much but do carry out a number of searches for the information.

About 5 years ago I had a loft extension and part of the deal was to have a combi boiler installed as well as an en suite with a crosswater shower from bathstore.

Alpha Combi Boiler CD32C
Crossways Thermostatic valve

My problem is that the shower has become a bit hit or miss with either piping hot water or stone cold water and unable to regulate the temperature.

So, basic checks already done:

• Hot and cold feed going to correct side of the valve
  Cold operating pressure ok
  Hot water to taps in the house fine
  Central heating works fine
  Removed cartridge and cleaned up and appears to be ok
  Living in very hard water area

I have easy access to front and back of the shower as well as the pipework

I have family coming over for Christmas so would like to know if there's any other checks I could do before getting someone round.

I know the replacement cartridge is about £75 but would like to confirm if this is the problem before I splash out money (pardon the pun)!

I can post pictures if required.

 

[Whitespirit66]

Feel the hot pipe to the shower. When shower runs cold, is the pipe still hot?

Are there any filters that need cleaning in the valve?

If pipe is still hot when shower runs cold, I would suspect cartridge.

 

[BONZO-84]

Cheers!

Shower on - cold water only, hot feed pipe cold, Fan runs but no ignition

Shower on - bathroom tap on - hot water, hot feed pipe hot, fan and ignition - shower runs hot, unable to regulate.

 

[BONZO-84]

Decided to take the plunge and shell out £75 for a replacement Crosswater Thermostatic Cartridge - CP0000250

Will post back later this week after i've fiited it and let you know if it's solved the problem.