I am soon to modernise an S plan heating system. I plan to add thermostatic valves to most radiaters, excepting those in lounge that are controlled by the room stat. I assume i will also need to put in a auto bypass valve. Immediately after the pump is the T where the CH and HW pipes part, followed by the two valves. I plan to take the bypass pipe from here . The return pipe is out of convenient site below the floor, and the only bit showing is a 15mm bit from the outlet through the tank and also going into the floor. I have read that a bypass needs to be in 22 mm, but as the tank return is in only 15mm and this is where i can conveniently get too,it is in your opinions ok to have the bypass in 15mm also. It seems to me that if 15mm has been fitted on this pipe there is no point in having a larger one on the bypass. The boiler has no overrun and is an ideal balanced flue of some years, but reliable.
auto bypass valve
- Thread starter jep49
- Start date
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the cylinder may only be 15mm but where it joins the rads return and back to the boiler useally is 22mm.
But can i run the bypass into the 15mm pipe that is showing above floor, or do i have to pull up the floor to get to the 22mm rad return? Is it good enough to go into the 15mm pipe given that when the system is on HW only this is all it is going through anyway.
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boiler details will help please?
B
Bambergaspipe
Not really, it should have been installed originally.
Where was that then, The Beano?, if the bypass is in 22mm then your flow will just keep circulating around the bypass and back to the boiler, don`t forget the gate valve in middle of bypass which needs to be in 15mm and needs to be fully closed then cracked open about half a turn.
Unless the floor is tiled, I would lift it and tee into the rad return.
You say you've got 11 rads. When the majority shut down on the TRVs, that water has to go somewhere, and it's not going to be happy going through 15mm.
You might be able to get away with a 15mm bypass if you also fitted a modulating pump. Don't take my advice on this though unless others agree.
I am a householder not a professional.
You say you've got 11 rads. When the majority shut down on the TRVs, that water has to go somewhere, and it's not going to be happy going through 15mm.
You might be able to get away with a 15mm bypass if you also fitted a modulating pump. Don't take my advice on this though unless others agree.
I am a householder not a professional.
B
Bambergaspipe
why?
and a plank.
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