Radiators needing bleeding

[freak_unique]

Hey, i have just recently moved into a rented house, and was having problems with my radiators making clanging, screeching, airy noises. the landlords came out and bled the radiators for us...and upon leaving said that the lady who lived here before us regularly had to bleed the attic radiator (it is an attic bedroom) weeklybecause alot of trapped air gets stuck in there. The thing is i dont have much experience of radiators...my mums house had themand they needed bleeding like once every few years! the house we lived in before this we never needed to bleed them once but these ones need bleeding every few days to stop the noise andwhen i bleed them so much air comes out! Does anyone know if this is normal?any advice would be great!

[Postdog]

I'm no expert, but maybe you have an airlock. A plumber might be able to advise, and there is a very helpful one who comes here sometimes, call, I believe, Gasman. You say you get air coming out though, and yet that is what is supposed to come out - once it becomes water, then you know the radiator is bled.

[jocky]

Sounds to me that air is being sucked in via the feed and expansion tank vent which being probably only about 4 foot above the hight of your attic radiator. With that radiator being right at the top of system the air is bound to accumulate, if you can find the pump (probably in the airing cupboard) there should be a switch on it which you can adjust, turn this switch down a notch and see if that helps.

[freak_unique]

Hey postdog - yeah thats right when i bleed the radiators alotof air cmes out for about 2-3 mins in each radiator until the water starts coming out which to me sounds like an awful amount of air to be coming out of each radiator every 2-3 days?all other radiators i have had have never needed bleeding every 2 days so there must be a problem?
Jocky - well, there is a small black tank thingy in the attic room in the built in cupcoard about 4 foot above the radiator maybe this is what you are talking about?Im ot sure i have no clue about this stuff. Well on the main boiler there is a switch (on/off) and a dial im guessing that is what you are telling me to turn down? But what does that dial do as i have turned it up before thinking it was the air pressure? Cheers hope you can help

[burkeas]

I don't know. Is the some kind of filter you can buy? If there is one I'd buy it. Maybe it would be worth it to get a new radiator. I truly don't know.

[maviscoull]

we had a problem with our daughters radiator as it always needed bled,it turned out that the whole system needed flushed and now there is no bother. i dont know how much that would cost as we are in a council house.

[jocky]

No I'm not talking about the switch on the boiler. The pump is probably in your airing cupboard where your hot water tank is, Should be the size of a large grapefruit and maybe by the make of grundfos or wilo on the nameplate here you should find a switch on the side where the cable goes in to marked 1, 2, 3. knock the switch down to the next number for example if it's set to 3 turn it down to 2 etc, see if that helps.

[jocky]

Pump should look a bit like this
http://www.plumbworld.co.uk/348-192

[woodchopper]

Make sure there is a corrision inhibitor added to the system - gas/air froms when the water without the inhibitor attackes the inside of any heating system without it.
There could also be a leak in the sytem that is letting air in.

[gasman]

Woodchopper has in my oppinion hit the nail on the head here. I doubt it would be the pump drawing as jocky suggests but it is a feasable option and well worth considering but as i said it is more likley due to corrosion or a leak. In corrosion situations hydrogen forms as a chemical reaction of the hydrogen molecules in the water breaks down with the contact of steel... It may well be hydrogen you are having to bleed out not infact air as you suspect !!! The only soloution is to flush, cleanse and add a suitable inhibitor to the system.
Or if it is a leak then it needs to be rectified and it is quite hard to locate a leak unless it is a gusher and leaves an obvious damp patch on the floor. but just a tiny trickle can cause what you describe and it could be evaporating on the hot pipes so you dont even know there is a leak. But often there is signs of a build up of scale around a leak as a tell tale if you know what to look for.

[freak_unique]

Hey many thanks guys, i have just accidently "found" the pump it was hidden above the boiler tank in a cupboard - i am tempted to try what jockey said about switching the switch down 1 but i was just wondering before i do this what does that switch control? I have just bled the radiators yet again. and upon switching the heating back on... the boiler/pump was making a bubbling gushing water sound...not a leak but sounds like all the air is still in there? any help would be great thanks :)

[woodchopper]

The switch controls the pump speed.