macdonalds Thermal Store pressure relief valves

[Plamber]

I have had to replace 3 this week, and lots of them recently. Does anyone else have this problems with them? The temp relief valves seem to be fine, just the pressure ones seem to wear down quite a bit.

 

[Dannypipe]

Can't say I've ever had to do it 3 times in a week! But yes it happens.

I work on lots of thermal stores, but mainly Gledhill.