Mira 915B

[PrenticeBoyofDerry]

Just doing a fault find on a Mira 915B thermostatic of a friends of mine, the water is struggling to get hot.
No blockages, the flow valve seems to be working correctly. So it must be down to the hot/temperature cartridge, the whole replacement is quite a tasty price, so was hoping to narrow the fault down, I would be guessing that the fault would be associated to the temperature spindle, would this be a fair assumption?
Or should I be looking at something else?

 

[stardanny]

Possible be temperature spindle is faulty. Can buy just the spindle. About £80

Is the temperature knob stiff, loose or feel different as before?

Have you tried overhaul, clean up and descale?

Is it this shower? http://www.showerdoc.com/mira-915-b-shower-spares

Daniel.

 

[PrenticeBoyofDerry]

The controls valve are nice and smooth, had both assemblies out and did a little non-invasive maintenance, did not want to start cracking nuts open and causing more aggro than needed, the shower I have been told is something like 30 years old, and is as you have linked. On the diagram it is assembly 14.
I have seen the temp spindle for around £25 but the full assembly is over £200!