Circulation

[Zagga1986]

Hi

Wonder if anyone has any advice before I go for the powerflush! I recently fitted a new boiler and replaced an old beast gravity hw with no controls. I put the system on an s-plan and everything filled nicely. I have all rads circulating apart from 2 downstairs rads. I had them luke warm and explained when I returned to replace valves and a radiator I will have a look into it. Found no issues so assumed an air lock. This time both rads were stone cold. I returned today and got one radiator hot and the other luke warm again, but once everything went back on they died out to tepid at best. I have balanced the system but they are both really struggling to return. Trv and lockshields are flying out when opened so I'm really confused as to what could be causing this! Any advice would be helpful. Ps there appears to be a loop or a bypass somewhere (appears to be under a concrete floor)

 

[Terrywookfit]

Could be one pipe system.

 

[Zagga1986]

You could be right, I had this discussion with somebody else actually. God I hope you're wrong. Thanks

 

[ianmcd]

By Pass will not be in a concrete floor, you will probably just have to install a restrictor valve on the return from the HW cylinder as if it was gravity this will be 28mm and you need to restrict this to force more flow to the rad circuit

 

[Zagga1986]

There already is one but thanks for your advice. Wouldn't expect there to be a bypass under a concrete floor but it's like there is a loop or a bypass under the floor, as it's circulating somewhere. I'm going with the one pipe system, will check that out first