Bottom Radiators not heating

Hi,

I have a gas bolir system. Recently, we were without heat for about a week, while we were getting a new solenoid fitted to the filter on the boiler. Since this was fixed however, when the heating is on, no heat is getting to the downstairs radiators, while the upstairs radiators are hot.

When I turn off all the upstairs radiators, the downstairs radiators heat up no problem, but will not heat when both upstairs and downstairs are on simultanously.

I tried to bleed the downstairs radiators in case there were airpockets, but water came out immediately, with no hissing air.

Any ideas? Before the heating was off for a week while the filter was being fixed there were no problems.

Thanks in advance, David

Could be sludge has settled in the pipes, blocking them a bit. Take a bad rad off for a manual flush in the garden, and see what you get out of it.