Air in Central heating system making noises

[Sartob]

I recently had a new hot water storage cylinder to replace my old one. I have a Worcester Greenstar 40cdi regular gas boiler and also a gas Aga. It is not a combi boiler and we have a water tank in the loft. It all worked fine until the new cylinder was installed and since then we have suffered from what sounds like trapped air and rushing water through the pipes, loud enough to wake me up. If the heating is on, the radiators make a noise as though filled with air but no air comes out when you try to bleed them. However the pipes under the floor upstairs make a noise in the middle of the night when the boiler is off and not making any hot water or heating. It is a wooshing sound that lasts about 20 seconds, stops for another 15 seconds, then starts again. My plumber has no idea why it is making this noise. He thinks it might be linked to the aga but they didnt change any pipes, just the cylinder. Has anyone got any suggestions or ideas as I am at my wits end as it keeps me up every night. At least we have heating and hot water though but the noise is so annoying and the radiators are not as hot as they should be

 

[RWebster]

Hi Sartob. It sounds to me like the person who installed your cylinder hasn’t aired the system properly when draining the system then refilling it upon completion. My best advice would be to turn every radiator off (turn thermostats down to 0 on one side, remove lock shield cover and use a spanner/adjustable to close off the other side clockwise until it’s completetly shut, hand tight will do). Do this to every radiator, apart from one. The radiator that you’re leaving open turn the stat up to 5. Give it 10/15 mins then bleed that radiator. Hopefully that should force all the air into the one radiator and you can get rid of the air. Failing that, I’d call the guys back who done cylinder and advise them to sort it.

 

[Sartob]

In hindsight, wondering whether I should have gone for a megaflow system but it was double the price. Does that system mean there is never any air in the system or could I still have problems. The guys who installed it have already come back but they dont know what to do. They have tried to bleed the system but are stumped. I need an expert near to Guildford.

 

[Mottie]

Although I didn't actually 'suffer' from air noise in the pipes, I could hear it from time to time and I used to bleed one radiator now and then. Someone on here mentioned an air separator which automatically removes air - even 'micro bubbles'. I fitted one (you fit them as near as you can to the outlet of the boiler) and I haven't had so much as a drop of air in the system. Don't know whether that will work for you but it did for me and was very easy to fit. I fitted one of these: https://www.jtmplumbing.co.uk/water...pJ1yqDsZpJAY9I8tNef0A5MhOc1DlC8BoCHbQQAvD_BwE

 

[ianmcd]

Hi Sartob. It sounds to me like the person who installed your cylinder hasn’t aired the system properly when draining the system then refilling it upon completion. My best advice would be to turn every radiator off (turn thermostats down to 0 on one side, remove lock shield cover and use a spanner/adjustable to close off the other side clockwise until it’s completetly shut, hand tight will do). Do this to every radiator, apart from one. The radiator that you’re leaving open turn the stat up to 5. Give it 10/15 mins then bleed that radiator. Hopefully that should force all the air into the one radiator and you can get rid of the air. Failing that, I’d call the guys back who done cylinder and advise them to sort it.

Dont touch the lockshields they are set to balance the system , if you dont know what you are doing you will unbalance the system