Central heating

HOMER · 2nd March 2009, 08:07

Does anyone have any central heating experience I know GG was in this line at some point ,I seem to have some air in the system as I can actually hear the knockeing sound in the pipes move around

I've bleed the radiators and still get the noise,I can stop the noise by traceing it to a radiator and giveing the stat a tweck and that stops it but it's not always the same rad, it's not all the time but quite regular, so what can I do ,where does the air build up from and is it a big problem I'm going to have ?

scgfull · 2nd March 2009, 09:39

Not an expert but from my experience with a conventional heating system (normal boiler, hot water cylinder and expansion tank in loft) this constant requirement for bleeding is probably due to lack of water in the expansion tank.

Some expansion tanks do not have a permanent feed controlled by a ball valve and so over a period of time the water drains away.

My advice would be to check your expansion tank in teh loft and top up with water and inhibitor as necessary. If it has a ball valve, check it's operating correctly.

GERFIX · 2nd March 2009, 09:52

I've recently totally emptied, re-filled, flushed, emptied again etc, etc. I took off the bottom two radiators and took them outside to flush through with a hose and you would not beleive the amount of black build-up that came out of both. It was thirty-odd years of build-up and must have formed a triangle from the inlet to the outlet pipe of each one.

It could be build-up such as this, and scaling inside the boiler which is causing your banging.

I'm no expert, but I'd certainly recommend getting a good quality descaling type flush such as Fernox and let it do it's work. If you are brave enough flush the radiators as I did, with a hose (outside of course!). If you do this, turn them upside down and repeat - you'll be amazed at how much NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- there can be in there.

It's not a five minute job but well worth the effort.

THIS may be of some help too.

2nd March 2009, 08:07	#1
HOMER Gets stuck in MG ZT 190+ 2.5 V6 Sadly no more Join Date: Nov 2006 Location: Doncaster Posts: 639 Thanks: 0 Thanked 1 Time in 1 Post	Central heating Does anyone have any central heating experience I know GG was in this line at some point ,I seem to have some air in the system as I can actually hear the knockeing sound in the pipes move around I've bleed the radiators and still get the noise,I can stop the noise by traceing it to a radiator and giveing the stat a tweck and that stops it but it's not always the same rad, it's not all the time but quite regular, so what can I do ,where does the air build up from and is it a big problem I'm going to have ? __________________ [SIGPIC][/SIGPIC] Des Member 426

2nd March 2009, 09:39	#2
scgfull Loves to post none Join Date: Jun 2008 Location: resigned - but can't get off Posts: 286 Thanks: 0 Thanked 0 Times in 0 Posts	Not an expert but from my experience with a conventional heating system (normal boiler, hot water cylinder and expansion tank in loft) this constant requirement for bleeding is probably due to lack of water in the expansion tank. Some expansion tanks do not have a permanent feed controlled by a ball valve and so over a period of time the water drains away. My advice would be to check your expansion tank in teh loft and top up with water and inhibitor as necessary. If it has a ball valve, check it's operating correctly. __________________ Steve Memeber 4069

2nd March 2009, 09:52	#3
GERFIX I really should get out more....... MINI COOPER S Join Date: Nov 2007 Location: Tranent, East Lothian, SCOTLAND Posts: 2,834 Thanks: 0 Thanked 0 Times in 0 Posts	I've recently totally emptied, re-filled, flushed, emptied again etc, etc. I took off the bottom two radiators and took them outside to flush through with a hose and you would not beleive the amount of black build-up that came out of both. It was thirty-odd years of build-up and must have formed a triangle from the inlet to the outlet pipe of each one. It could be build-up such as this, and scaling inside the boiler which is causing your banging. I'm no expert, but I'd certainly recommend getting a good quality descaling type flush such as Fernox and let it do it's work. If you are brave enough flush the radiators as I did, with a hose (outside of course!). If you do this, turn them upside down and repeat - you'll be amazed at how much NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- there can be in there. It's not a five minute job but well worth the effort. THIS may be of some help too. __________________ .......................................Colin http://i245.photobucket.com/albums/g...Cooper-S-2.jpg