oxi mixer shower

[williams932]

just suddenly stopped bringing the boiler in unless on max hot,bring the cold in slightly and the boiler cuts out? too much cold pressure?failing non return? help it's been fine for 2 years.stripped it and blown through the non returns ok,ceramic discs ok?scratching my baldy head!!

 

[seco services]

try running a hot tap as well.
you may find its boiler related rather than shower but showers can detect the fault first.