Unable to add water to system

[danboy775]

I have a worcester danesmoor boiler with an open vent gravity primary system.
My kitchen radiator fell off the wall yesterday, i never used it so i just disconnected it. One of the valves was leaking all day and all night so i lost quite a bit of water from the system leaving the 3 radiators upstairs completely empty of water.
I found the feed cistern and it was full of water but it does not seem to be refilling the water lost through the leaky valve.
Can anyone with experience in the type of system give me some pointers?
Thanks

 

[Armo74]

If there is water in the feed and expansion tank then the cold feed will be blocked.
If the cold feed is blocked its probably from sludge being pulled down from the tank as you were losing water.
The system and the tank could probably do with a good clean.
Photos will help us point you in the right direction of the cold feed.

 

[danboy775]

Apologies for the poor pictures. The first one is where the cold feed comes out of the back of the tank, from this point it dissapears behind the wall

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• danboy775
• 14 Jan 2015
• 1

These two are of the pipes either side of the boiler, i'm not sure which is the cold feed.

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• danboy775
• 14 Jan 2015
• 1

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• danboy775
• 14 Jan 2015
• 1

This one shows the amount of sludge in the bottom of the tank

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• danboy775
• 14 Jan 2015
• 1

are there any tests i can do to rule out airlock or cold feed blockage?

 

[GeorgeNewman]

You might try clearing the apparent blockage in the cold water feed using compressed air.

Using a garden sprayer such as a Outdoor Hozelock sprayer, tape around the end of the nozzle with pvc tape. Pump up the tank with air and then apply the nozzle firmly to the water feed outlet at the bottom of the open vent header tank and operate the sprayer. Then flush the system through with plenty of water if successful.

If you have a decent seal you may be able to clear the blockage with the air pressure. In any case this would be a simple and safe first step before calling a plumber in.

 

[danboy775]

thanks for the advice.
I did manage to get water back into the system though, I just filled it up through the vent discharge