Hot water but cold radiators

[PaulD]

Hi, I have an old hot water radiator system with a seperate circuit for Hot Water Only.

With Autumn approaching, I have tried to switch it from HW only to CH but the radiators do not heat up.

I have bled the radiators at the top of the house and found no air bubble.

(Q: DO I JUST NEED TO TRY THE ONES AT THE TOP ARE MUST I BLEED ALL RADIATORS)

Has anyone any tips on what the problem could be?

Any help appreciated.

 

[ChrisR]

Lots of possibilities Paul, often it's a pump , if it doesn't get used for the HW. Depends on what your system has. You could also have one, or two motorized valves, which can have stuck or need new bits.

 

[PaulD]

Thanks Chris,

I guess that it's gone beyond what I can reasonably tackle myself. Time to call in an expert.

I really appreciate your timely reply.

All the best!

Paul