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G

gary50

I have basically always been under the impression that if a boiler was specced wrong the hot water would run cold. I.e if you have 20lpm with a boiler that delivers 12lpm then you would still get 20lpm coming out the hot tap but it would only run warm as the boiler cannot handle the flow of water passing through the heat exchanger.

I have recently been told by Vallaint that the boilers have flow restrictors which will actually only limit the flow of water to the manufactures flow rates. So a 12lpm boiler will only ever allow 12lpm to exit the hot tap due to the restrictor.

i aslo phoned Worcester and they were a bit vague. They actually didn't know the answer and said although a flow restrictor was fitted it wasn't actually accurate.

Im pretty sure I've seen boilers with low flow rates fitted to cold water mains more powerful than the boiler flow rate and they still allow the maximum amount of water to pass.

So my question is who is right? this is very basic plumbing stuff but know of the manufactures appear to give a straight answer! Its almost like know one knows for sure!
 
Flow restrictions fitted. Installed a 24 pro Vaillant the other weak, cold flow rate was 22 l/pm but hot output when I commissioned was 9 l/pm.
 

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