Only half the radiators heating up

[W1kins]

Hi, I have a pumped gravity fed heating system with 9 radiators on it but only five get warm the others do not heat up at all, the pipes on the TRV side gets hot on all radiators but the pipe from the lock shield side is cold on all the radiators that do not get warm, I have had the system balanced but has not made a difference and even the radiators that do warm up take a long time to do so.

If anyone could help with any advice it would greatly be appreciated

Many thanks

 

[Agile]

Blocked/weak pump?

Sludge?

Professional balancing needed?

Same old causes in every case!

Tony

 

[buck51]

Remove the heads from the TRVs and check the pins are not stuck in the down/ closed position

You should be able to press them down and they should spring straight back up to the open position

let us know the results