Continuous air in rads?

[houstonwehaveaproblem]

Daughters bedroom radiator constantly requires bleeding. On some occasions I bleed it and the air stops but no water comes out. After bleeding it lastime I noticed the rad in the next room was cold so I bled that one. Now the rad in the room directly below is completely cold!

This is a continuous saga in our house.

Can anyone advise me on what the problem may be or what I can do to rectify it

 

[plumbswe]

Much more information needed. What type of system do you have for a start

 

[Maxsys]

What system do you have, combi, open vent, sealed etc...Boiler make and model, and when was it last serviced? Do you know if you have inhibitor in your system?

 

[houstonwehaveaproblem]

Excuse my ignorance as I don't know much about boilers etc.

Basically there is an Immersion tank in cupboard downstairs. Boiler in roof space upstairs along with water tank (converted bungalow)

8 x radiators in property.

Boiler is a micron gloworm and it's vented through the roof

 

[JohnD]

bleed it when it is off and the pump is not running.

there are various models. is there a pressure gauge on the boiler? what does it read?

if not, go into the loft, look for the feed and and expansion tank, see how much water it has, and how much mud in the bottom. When you move the ball valve does it start to top-up with water? Are there any labels or containers of corrosion inhibitor?

how old do you think the system is?

 

[houstonwehaveaproblem]

bleed it when it is off and the pump is not running.

there are various models. is there a pressure gauge on the boiler? what does it read?

if not, go into the loft, look for the feed and and expansion tank, see how much water it has, and how much mud in the bottom. When you move the ball valve does it start to top-up with water? Are there any labels or containers of corrosion inhibitor?

how old do you think the system is?

Tried bleeding with the pump off but no change. No signs of inhibitor.

System about 12 years old. To be honest it's never been serviced

 

[JohnD]

And the pressure or tank?

 

[Poisonata]

Hello,
First off I'm not a plumber, just felt I might have something to offer the thread.
We had a similar scenario albeit with a fairly modern boiler (radiators, pipework much older), everything worked fine however I was constantly bleeding a radiator full of air every week or so.
It was suggested to me to take the following courses of action:
1. Ensure sufficient inhibitor in the system (I ended up putting in double the minimum requirement) though I couldn't believe all this gas was due to corrosion else my radiators would be falling apart by now.
2. Reduce the pump speed (3 speed settings), as it was on the highest I reduced it from 3 to 2. If it had been on 2 already I would have probably left it alone.
3. Check the flange on the pump inlet for any sign of leaks. What I was unable to understand was in a pressurised system how could air possibly get in. As the water rushes into the pump at speed, it is possible for air to be drawn in aswell if the seal is damaged without water squirting out.
4. Finally a litre of good quality leak sealer. At first I was unhappy about introducing a litre of 'goo' to the system however after a little research I now understand stuff stays in suspension unless it comes into contact with air when it forms a powdery paste.
These four measures did the trick for me, now after a week I get the equivalent of 1/4 of a cup full of water in air out of the highest radiator. I also added a Fernox magnetic cleaner though I suspect this was overkill.
Best of luck fella !

 

[Agile]

Hello,

I like that screen name!

It sounds like an Italian tragedy.

Makes me think of a sexy older woman like the one in the film Phaedra!

 

[houstonwehaveaproblem]

And the pressure or tank?

Tank looks ok

Here is a pic of the pressure gauge and the set up

 

[Agile]

What we can see looks quite good.

But I would advise running at about 0.8 Bar pressure when cold.

Tony

 

[houstonwehaveaproblem]

What we can see looks quite good.

But I would advise running at about 0.8 Bar pressure when cold.

Tony

How is it adjusted?

Thanks

 

[houstonwehaveaproblem]

Ok, I got the pressure up to 0.8 now

 

[houstonwehaveaproblem]

So.... after upping the pressure gauge I bled my daughters bedroom rad again and got air out until water appeared. All radiators nice and hot.

Half hour later daughters bedroom rad stoned cold again!

 

[GasSafeTony]

iron grabs the Oxygen from the water, makes Iron Oxide (= rust) and you're left with hydrogen - which is why you possibly keep having to vent your sealed system. If you put a corrosion inhibitor in your system it will stop the reaction, and you won't have to bleed your rads any more.
£10 to £15 fom any DIY store.