shower problems

[darrenangel]

I have a thermostatic shower valve(not sure what make). Its run on a twin pump. Recently the shower loses pressure after a few minutes of it running. Then if you leave it a while it will run ok then lose pressure again. I thought it must be the cold feed to the pump or the cylinder feed. The cylinder feed has 2 gate valves a newish one and an older one that doesn't appear to work. It has run fine over the last couple of years but is it possible that this faulty gate valve is partly closed and is now blocking up. Any ideas would be greatly appreciated.

 

[Billy Bob Bob]

that could be happening but do a basic check first,check the tanks ball valve if blocked and not able to fill quick enough there's your problem

 

[darrenangel]

the tank seems ok. its always full. I thought that might be the problem but whenever the problem occurs the tank is always full of water, any other ideas there would be of value.

 

[Billy Bob Bob]

when its in use does it re-fill quick enough?

 

[darrenangel]

we have a 50 gallon tank and when the problem has occured i've been in the loft and the tank is being replenished at the same rate water is drawn from it, so I don't think its the ball valve.