We have a copper hot water cylinder connected to a solar system. For a while we have had the odd overflow open up on the cylinder and lost pretty much all the hot water.
The cylinder has a safety pressure release and temperature release valve set at 3 bar and I think 70°C.
I messured the pressure in the expansion vessel and found it to be between 3 - 4 bar at times.
The water board said good pressure, just put a pressure reducing valve in to limit it. I did only to then find that very close to the cylinder we had a PWC 2.1bar valve anyway which I had forgotten and still we are loosing water.
Today I checked the system.
It was not the temperature - 25°C in the morning.
The inlet pressure was double checked with 2 PRVs.
So I thought that the only other possibility could be the outlet for the hot water into the house.
We have two shower mixer valves connected and a few hot and cold taps.
I isolated all the water supplies individually and only when a downstairs showerroom is on, the water pressure in the cylinder rises above release pressure.
So I assumed that there is backward flow through the mixer from cold to hot.
The mixer is a grohetherm 3000 19663.
Can this mixer not handle different pressures (2.1bar and 3 - 4bar) on cold and hot water, is the mixer cartridge for hot and cold broken or do I need another presure reducing valve for the cold supply in the downstairs shower room?
The cylinder has a safety pressure release and temperature release valve set at 3 bar and I think 70°C.
I messured the pressure in the expansion vessel and found it to be between 3 - 4 bar at times.
The water board said good pressure, just put a pressure reducing valve in to limit it. I did only to then find that very close to the cylinder we had a PWC 2.1bar valve anyway which I had forgotten and still we are loosing water.
Today I checked the system.
It was not the temperature - 25°C in the morning.
The inlet pressure was double checked with 2 PRVs.
So I thought that the only other possibility could be the outlet for the hot water into the house.
We have two shower mixer valves connected and a few hot and cold taps.
I isolated all the water supplies individually and only when a downstairs showerroom is on, the water pressure in the cylinder rises above release pressure.
So I assumed that there is backward flow through the mixer from cold to hot.
The mixer is a grohetherm 3000 19663.
Can this mixer not handle different pressures (2.1bar and 3 - 4bar) on cold and hot water, is the mixer cartridge for hot and cold broken or do I need another presure reducing valve for the cold supply in the downstairs shower room?