No hot water after drain down

[JUK]

Hi folks, hoping for a bit of advice please!

I have an open vented system which I've recently drained down in order to adjust some pipe work for a new towel radiator in the bathroom (not yet fitted).

I've now refilled the system and bled all the radiators (with the exception of one which has a rounded bleed valve) and the radiators work as normal, but no hot water. The boiler kicks in for around 10 seconds, then cuts out and restarts. Now having to use the immersion heater as a backup.

Unfortunately I did not have the foresight to check the F&E tank before refilling, but I've since checked it and found that it is FULL of sediment, some of which will have made it into the tank.

I've tried manually opening the valves and opening the bleed valve in the first pic, with no joy.

I don't know whether the issue is an airlock or a blockage, so hoping someone can shed some light on possible causes and hopefully a solution.. I have attached pics of my setup.

Thanks in advance

 

[terrymac]

The coil inside the cylinder may be full of air. There is a manual vent ,it's the brass fitting on top of the vertical pipe ( painted grey),just above the motorised valve. Manually latch the motorised valve ,whilst bleeding air from the vent. And don't have the heating / pump running whilst doing so.
After air is expelled you will get a stream of water, be prepared to contain the water with a large towel,let water run for a little while as more air may still be present.

 

[JUK]

Thanks for your reply.

I've bled the vent with the valve open, but only a very small amount of air came out then water, which I allowed to run for about 10 seconds. The boiler is still in a restart loop.

Do you have any other suggestions?

Many thanks