Thermostatic shower mixer - not going hot?

[Nomad]

Hi. The mixer shower was fitted new 2 years ago during a bathroom refit and worked fine, temp range cold to hot.
It’s not been used for a few months, now temp range is cold to room temp.
It has a safety lock you need to press to go above 38* - button is pressed but temp is still low.
Hot supply pipe into the tap is hot so the problem is internal not the water supply.

The bathroom sink next to the shower has hot water & good pressure.

Any practical suggestions from good folk with experience?

Shower under 24*


Sink next to it over 30*


The system is solar so all temps will rise if / when we get sunshine, 30 would be ok for now..

Many thanks.

 

[addjunkie]

Take it to bits and clean everything. If that doesnt fix it, replace it.

 

[voipio]

If 30.8 degC is the temperature of the hot water supply, a thermostatic mixer may well struggle to get close to that. Try and get the hot water tank to 45 degC, or more, and see if the thermostatic mixer's temperature range is more acceptable.

 

[Nomad]

Good point about the temperature difference - will give the tank a few days to heat up now we are getting sunshine, will use immersion if needed then retry..