Cold rads downstairs

[aceone]

hi...i have 2 rads downstairs that wont get warm, even the pipework to the rads are stone cold,system has been bled apears ok......8mm system, combi boiler fitted in attic, rads upstairs ok.........any ideas.......was wondering if it was due to sediment in system,,,,does sediment tend to build up downstairs,due to gravity?.......thanks for your advice in advance .....thankyou

 

[BenC]

can you hear the pump working on the boiler?

 

[Mbear]

hi...i have 2 rads downstairs that wont get warm, even the pipework to the rads are stone cold,system has been bled apears ok......8mm system, combi boiler fitted in attic, rads upstairs ok.........any ideas.......was wondering if it was due to sediment in system,,,,does sediment tend to build up downstairs,due to gravity?.......thanks for your advice in advance .....thankyou

it'll most likely be caused by one of these 3

1. the pump is possibly struggling to push the water to the last rads.
2. The trv pins may need greased or the trvs may need replaced
3. If you have flow and return manifolds on the system then there is a possibilty that one or the other may be choked causing your issue. If you can find the manifolds the easiest way to check if it's choked with sludge is to get a fridge magnet and see if it sticks to the copper pipe/manifold. The magnet will not stick to copper pipework that is not choked.

 

[peteisfishing]

Could be as simple as balancing the system, try closing off the lockshield valves on the rads up stairs a 1/4 turn on each, and see if that improves things