Central heating problem!!!!

[andyd2001]

I have drained down my system to flush it out as it was full of sludge etc.

I had probs draining the system because of an air lock. Managed to drain down in the end...

I am now removed all crap from header tank, replaced float valve and put water back on to fill system. The header tank has filled (and stoped very quickly), so the system has no water in it. I am thinking that there is an air lock in the cold water supply pipe. I have searched high and low for any other bleed valves etc and can't find any.

Any ideas anyone?? I am starting to get cold now....

 

[baxpoti]

Probably blocked the feed pipe from the header, with all that rubbish you removed
is it a 15mm or 22m?
if its 22mm you can try a hose down it!

 

[andyd2001]

i just shutdown the valve in the cold feed and removed pipe from one side. pretty clean, undone the valve slightly to ensure that it wasn't sticking. and it wasn't (i got a good soaking).

Turned on pump and set motorised value to both heating and hot water, heard a bit of a bang and ground floor rads started to fill. I bleed all ground floor radiators till air stopped. but there is not water coming out, so must still be an airlock somewhere??? tried opening all bleed valves (1 at a time) and still doesn't seem to be filled..

 

[HarrogateGas]

Does the cold feed rise at all in the loft from where it leaves the tank to where it drops downthrough the ceiling?? That can be a common place for the feed to airlock.

 

[andyd2001]

No the cold feed pipe more or less drops straight down. and it doesn't rise it all falls.

i just opened the drain valve to make sure some water has got in. but only trickles out...

 

[andyd2001]

anyone???

 

[Nige F]

hose on a drain cock downstairs .....other end on mains cold ....someone in roof to check water levels .........then blast the bastard back up

 

[andyd2001]

Thanks mate that worked a treat.....

At least I won't have girlfriend moaning that the house is cold 2nite.

Harsh thing is that I got to do it all again tomorrow to remove the flush i put in..... Oh well at least i know what to do now....

Thanks again............