My apologies, certainly not my intention. I have a little but not much knowledge on all this.
Above the pump is a T valve - one 22mm goes to a 2 way valve which goes to the middle of the cylinder and seems to be the hot water from the boiler.
The other 22mm from the pump itself goes to a T one side of which goes to a 2 way valve which I think controls CH - it goes down through floor.
The other side of this second T is the bypass pipe which you are interested in - it is 15mm with the red gate valve in the middle.
The other end of the bypass connects not to the bottom of the cylinder itself, but to a 22mm pipe going from the bottom of the tank down through the floor. This is cooler than the other 22mm into the tank so I assume is the return to the boiler.
The rads do all have TRVs, but I have (already) removed the top of the one in the hall so that it cannot shut.
I cannot actually see the pump setting as it is behind the pump, but it seems to be on the middle setting of 3 possibilities - so presumably 2.
The only other thing I can think of, mentioned early in the thread, is that the cylinder is "solar ready", so I don't know if that would provide the need for a bypass - apparently the switch over when/if we install solar is simple for a plumber, but involves changing some of the connection points already established to the cylinder.
The noise is I'm afraid still sometimes present, especially when the water in the cylinder is hot - but doesn't seem so loud.
If you do have any final thoughts on other things I could try (e.g. things to "tune out" the noise sounds worth a try) then I'd appreciate it.
For now I will leave eveything as it is, with the bypass valve closed, over a period of time to see what happens.
Very many thanks to you for your perseverance, very much appreciated.
If anything dramatic changes I will firstly try opening the bypass valve by 1 turn - if still a problem I will update this post.
Regards and thanks again,
Geoff
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