bypass valve - manual vs auto

[wallacengrommet]

Hi
I have a bypass valve fitted between the cyclinder coil and just before the motorized valve, can anyone tell me if this is to ...

a, control the temp\flow through the coil inside the cylinder
b, like a manual ABV - to keep flow consistent when TRVs are closed on rads
c, a safety feature to provide a second path for water should the motorised valve become blocked (ie to protect the pump).


b+c don't make a lot of sence because you would want an Auto bypass valve in this scenario ?

I think the answer is A - and it is used when balancing radiators - ie you don't want full flow thru the coil as it will rob pressure for rads ?

 

[kbdiy]

I assume you are saying it is manual - so possibly a gate valve? If so, it cannot be a bypass if it is fitted inline with the cylinder coil as you describe. For it to be a bypass it would have to tee off to an alternate circuit.

What you have described (I think) is a simple manual flow control valve - so 'A' in your list.