Thermostatic cartridge keeps failing - back pressure?
Hoping to get some advice. Been in this house 10 years and shower worked fine but now on my third shower cartridge in two years. I have descaled them all, scrubbed with a toothbrush and used plumber’s grease when they stopped working but that doesn’t get them going again.
I’ve read through the advice online, the boiler temperature is 50-60° so not too hot, and there is a pressure reducing valve on the cold supply. But I came across a small bit of info about back pressure. I have a flow restrictor and water saving shower head supplied by the water company - could this be causing back pressure which makes the cartridges fail?
Hoping to sort the cause before I spend another £75 and break that one too! It is the type with the big spring and no mesh