Re: CH/HW emergency - Help !!

[Dave Liquorice]

Any suggestions gratefully and desperately received -

How much gung/sludge is in the bottom of the expansion tank? Draining might have drawn some into the system causing a blockage.

Though I suspect it' more likely to be a problem with valves not being open to let the air out and the water in. See if excercising the system to see if you can get things shifting. Most motorised valves have a manual device for opening them. Use it and open all valves, 3 port ones set to their mid position so all the ports are connected top each other. Also switch the boiler off on it's own switch or thermostat to stop it firing on a possibly dry boiler.

the thought of calling out the plumber to fix my DIY is too > embarassing to contemplate !

He he...

[Stephen Wilson]

Dave, You are a lifesaver ! If you live anywhere near Milton Keynes, I'll buy you a beer, or several ! I drained the system down again and, lo and behold, the header tank wasn't draining, so I disconnected the outlet pipe and jubilee'd a hosepipe to it as per your instructions. Turning on the hose led to a sudden bout of gurgling, then water started spurting out of the open valve of a downstairs radiator (which I took to be a good sign!). The system refilled perfectly, better in fact than it has ever done in the 4 years that I have been living here (and I've been through the draining/refilling routine more times than I care to remember). The smart new rad. works well and we won't have to have cold showers tomorrow morning ! Thanks again, Steve

[Dave]

So did you use the mains just to unblock, or have you filled the whole system via the hose pipe? (just thinking it wouldnt have any corrosion inhibitor or anything in if you did that?)

[Dave Plowman]

By far and away the most likely cause is an airlock. To cure this, you could try draining down again and re-filling, but this probably won't work. The easiest way is to drain down, then fill via the drain point using mains pressure water. You'll need someone watching the header tank and as soon as water starts rising in this, stop.

[David W.E. Roberts]

Glad it worked for you! Cheers Dave R

[Christian McArdle]

If the cylinder, pipework, radiators and boilers are all man enough to take it, then convert the gravity fed system to a sealed pressurised one. Then you just don't get these problems. The kit of parts to do so is very cheap and you could probably fit it in the time it takes to sort out your airlock!

Christian.

[Steve Wilson]

I never knew that was possible. Any pointers on where to go to find out the pros and cons, and how to do it? Cheers, Steve