Radiators Won't Fill Up HELP!

[Muushy]

I drained down my heating system today to install 2 new radiators, both with two new trvs and two new lockshields. I started off by draining down the system by turning off the stopcock on the f&e tank. and drained down from the drain off valve on the last rad on the run. it took a long time to drain down the system. once it was drained down i installed the two new radiators and turnt the stopcock on, on the f&e, started to bleed the radiator but only a bit of air came out and no water. I was told this could be because of a blocked cold feed, so i used a hosepipe to blow up the open vent to see if it could push it out but still no luck! what could i do, any experienced engineers out there that have come across horrible jobs like this before i need your knowledge!

 

[sonray ltd]

when you drained the system did the f/e empty ?

 

[Muushy]

yeah the f&e did empty

 

[Mike Jackson]

Unlikely to be a blocked cold feed then unless some muck has dropped down as you drained down. It's probably airlocked. You could try a hose down the cold feed carefully or shut off the new rad valves, remove a radiator and use a wet and dry to try and get the water flowing.

Mike

 

[sonray ltd]

if it emptyed rare that it will suddenly block when refilling.

1st i'd try putting the motorised valve in to manual position as this can cause an airlock in the heating side.

one way to check the cold feed as you say put the hose in the vent pipe and feel the system feed pipe in the bottom of the tank.
you should feel the mains water come out there into the tank.

another way is drain the system again and leave the draincock open and when the f/e empty put the hose into cold feed in tank and flush it through.

 

[Muushy]

So what your saying is empty out the tank and shove the into the cold feed and blow down the feed on the bottom of the tank whilst the drain off is open on the rad and see if the water blows through?

what is a wet and dry mike jackson?

 

[sonray ltd]

yes. that will tell you its not blocked.
there is a number of ways to go about it.
i don't think you have a blockage.

 

[Deleted member 2053]

See if you have an air vent on the flow side of the HWC primary. Sometimes these cold feeds are configured such that you get nothing unless you bleed that first. Just come in from such a site.................

 

[Muushy]

what do you think it is then if its not a blockage? its driving me mental i cant suss it out

 

[mcmoby69]

without looking at the job and not wanting to insult anyones intelligence!is the ballvalve stuck? also some heating sytems fill up better with the pump off, others fill up better with the pump on. heating sytems are like women, they defy all laws 0f physics and logic! if that fails.disconnect one side of the lowest rad and run off a bucket or two, then do the same with the other side.

 

[Muushy]

but the tank filled up so its not ballvalve the water wont escape from the tank into the rads.and mcmoby69 would that get rid of an airlock if i drained a few buckets of water from the rad then?

 

[Mike Jackson]

what is a wet and dry mike jackson?

Wet and dry vacuum.

Mike

 

[Flush]

Just had the same happen today!

I have worked out the problem some sludge from the f and e tank had blocked the cold feed to the rads,

I have connected the mains direct to the cold feed to the rads and flushed out the system so all rads are full now.

Problem now is that the boiler is cutting out !

it did run dry for a couple of mins due to the blockage.

Any ieeas what the problem could be?

thanks