All Radiators not bleeding

[Ecocrop]

We have a bungalow and the heating has'nt been on for a while. It was put on and there were radiators which needed bleeding, which is normally no problem. however this time they would not bleed, there was no air and no water offering to come out in ANY of the radiators. The radiators are not blocked, in that all the bleed screws could surely not be blocked and this was checked anyway. It is not a sealed system and I checked the expansion/supply tank in the loft and it was ok with plenty water and no blockages. I assume, I hope correctly, that there must be an air lock somewhere in the system but I don't know how to find or fix it. There does not seem to be a bleed pipe in the loft, only an overflow pipe into the expansion tank. I would value any help or suggestions to the potential cause of the problem and how it could be resolved.

Kind Regards
Ecocrop

 

[croydoncorgi]

Make sure there's some water in the (small) F&E tank in the roofspace!

 

[namsag]

If the header tank is full there is a very good chance the cold feed from it is blocked where it tee`s into the boiler pipes.Can be unblocked sometimes by controlled tapping of tee with a hammer, but usually requires cutting out and clearing

 

[PTH]

I presume that you've checked that the radiator valves are open , and as it is reasonably warm you will need both valves open if you have thermostatic valves on the flow connections - I usually isolate all my radiators during the summer to keep the de-oxegenated water in them in case I have a leak or need to drain the system down.