Luke Warm Rads

[dk1uk]

Hi - any ideas as to why some of my rads are piping hot, yet others are only luke warm? The two pipes going into the rads in question - one is hot, the other (with the controllable valve) is luke warm.

I have bled them and have the controllable valves turned up high.

I have GCH - Potterton Flaming II boiler.

Bizarrely I have four wall-mounted thermostats in the house - two in one bedroom, one in the kitchen and one in the hallway. Even so, I can't imagine that the stats are controlling specific rads?

Might there not be enough pressure in the system to push the hot water around? If so, how would I check this?

Any ideas would be much appreciated.

 

[dk1uk]

Additional info...

I shut down all of the radiators downstairs except for the cool ones, and they've started to warm up.

Does this sound like a pump issue?

 

[D_Hailsham]

It's a balance problem.

Read How to balance a CH system.

If you want a quick and dirty method, start with the lockshield valves open half a turn. Then feel the return pipes on each rad. Those which are much hotter should have the LS valve closed an eighth turn and the colder ones opened an eighth turn. Allow the rads to adjust to the new flow rate (10-15 mins) before making any further slight adjustments.

 

[dk1uk]

Great - thank you - I will give that a try. Thanks again.

 

[dk1uk]

I have been adjusting the rads flow for a few days now and whilst the situation has improved, some rads are still not warm enough.

I'm not sure if this has any bearing, but I have 3 wall-mounted thermostats in my house. One in the hallway downstairs and then two in a bedroom upstairs. Can anyone perhaps explain why I might have more than one in a house - and certainly why I'd have two thermostats in the same room?

Many thanks