Loads of air in central heating.

[Chris12345678]

Evening,

I am getting a lot of air in my central heating system.
After turning the heating off, the header tank (in loft) is refilling for maybe 5 minutes, and you can hear the air passing through one of the upstairs radiators for a further 5 minutes.
I can't find any leaks and nothing is coming out of the overflow on the header tank?

Thanks.

 

[Chris12345678]

Oh, and the CAPTCHA thing on registration doesn't work on 'What is next day after Tuesday?'

 

[rpm]

Oh, and the CAPTCHA thing on registration doesn't work on 'What is next day after Tuesday?'

Just another day?

 

[ShaunCorbs]

Any work gone on with the system?

 

[Chris12345678]

Any work gone on with the system?

No, nothing at all.
I've always had air getting into it, and having to bleed maybe twice a winter, but this is silly!

 

[townfanjon]

Old system , pics of boiler and pipework may help .

 

[ShaunCorbs]

Could be corrosion producing hydrogen

 

[Chris12345678]

This might take a few attempts:

https://i.*********/RLP4eaB.jpg
https://i.*********/y0PWylH.jpg
https://i.*********/bwgyzec.jpg

 

[Harvest Fields]

Evening,

I am getting a lot of air in my central heating system.
After turning the heating off, the header tank (in loft) is refilling for maybe 5 minutes, and you can hear the air passing through one of the upstairs radiators for a further 5 minutes.
I can't find any leaks and nothing is coming out of the overflow on the header tank?

Thanks.

Any water leaking from the overflow outside when the heating is on?

 

[Chris12345678]

No, nothing from overflow at all.

 

[Harvest Fields]

No, nothing from overflow at all.

Is the water in the f&e hot when the heating is on?

 

[Chris12345678]

Is the f&e tank the one in the loft that feeds the cylinder (pipes are at the front of the cylinder in the picture)?

If so, I don't know, it's in the loft and the kids are in bed so I can't currently go up there!

 

[Harvest Fields]

Not the one in the picture. The one in the loft that feeds the boiler

 

[Chris12345678]

That's the one I was meaning. I can't get up in the loft at the moment, kids are in bed and the ladder is under their bed!

I suppose it could be sucking in air via the cylinder vent that goes to the f&e tank?

 

[Harvest Fields]

That's the one I was meaning. I can't get up in the loft at the moment, kids are in bed and the ladder is under their bed!

I suppose it could be sucking in air via the cylinder vent that goes to the f&e tank?

Nope. Separate circuit

 

[Harvest Fields]

Something about this picture looks funny and I cannot put my finger on it?

 

[Chris12345678]

There are no valves to separate the heating / central heating circuits.
Does that make a difference?

 

[Harvest Fields]

There are no valves to separate the heating / central heating circuits.
Does that make a difference?

The system will be gravity. Your hot water that comes out of the taps and the heating water are completely separate mate.

 

[Chris12345678]

Yes, but there are two pipes coming out of the front of the cylinder that go to the tank in the loft. One is a feed and one is a expansion pipe(?) from the cylinder isn't it? Could it be sucking in air from the expansion pipe(?).

Thanks.

 

[Harvest Fields]

Yes, but there are two pipes coming out of the front of the cylinder that go to the tank in the loft. One is a feed and one is a expansion pipe(?) from the cylinder isn't it? Could it be sucking in air from the expansion pipe(?).

Thanks.

Yes it could. Is the 22mm pipe hot all the way up?

 

[Riley]

Yes, but there are two pipes coming out of the front of the cylinder that go to the tank in the loft. One is a feed and one is a expansion pipe(?) from the cylinder isn't it? Could it be sucking in air from the expansion pipe(?).

Thanks.

If it’s plumbed wrong then yes but if it’s worked fine up till now then Doubtful. The pipes out of the front of the cylinder are flow and return from the boiler

 

[Chris12345678]

It has worked fine until this week. I'm worried that a blockage somewhere will be causing it to suck in air from the expansion pipe(?).

I will have to check tomorrow night as the cylinder in also in the kids bedroom!

Thanks for your help

 

[Harvest Fields]

It has worked fine until this week. I'm worried that a blockage somewhere will be causing it to suck in air from the expansion pipe(?).

I will have to check tomorrow night as the cylinder in also in the kids bedroom!

Thanks for your help

The reason I asked about the pipe being hot and the water in the f & e being hot is sometimes they can pump over. This will definitely be sucking air in if it is.

 

[Mdljk]

5 minutes refilling the f&e tank every time you switch heating off. That is a lot of water going somewhere. Sounds to me like you have a leak in your heating pipework. If it was upstairs you’d see it coming through the downstairs ceiling so it may well be that a heating pipe hidden under the downstairs floor has sprung a leak in the cold weather?

 

[Harvest Fields]

5 minutes refilling the f&e tank every time you switch heating off. That is a lot of water going somewhere. Sounds to me like you have a leak in your heating pipework. If it was upstairs you’d see it coming through the downstairs ceiling so it may well be that a heating pipe hidden under the downstairs floor has sprung a leak in the cold weather?

Not a bad shout to be fair.

 

[Riley]

I did think that but I maybe misread that it was refilling from pumping over??

 

[Mdljk]

Worth trying to eliminate the more obvious first I’d say.

 

[Harvest Fields]

Worth trying to eliminate the more obvious first I’d say.

Looking in the loft would definitely be easier than lifting boards.

 

[Mdljk]

Any downstairs room currently started showing signs of condensation perhaps?

 

[SJB060685]

Is that pump in boiler mounted on return?

 

[Chris12345678]

After bleeding it earlier this evening, it was on for a few hours being very slow to get warm.
After turning it off it was refilling for at least 15 minutes until I turned the valve off.

No signs of condensation.
There’s still air moving around quite loudly 20 minutes after turning heating off.
All downstairs pipes are buried in the concrete floor.
Worrying.

 

[Mdljk]

If you look near the roofline outside you will see the ‘overflow’ pipe coming from the f&e tank for the ch. when the heating is on tomorrow look to see if any water is coming through that pipe. If it was ‘pumping over’ water coming out of that pipe could confirm it. If not and you are still losing water then that water has to be going somewhere else ie a (likely) leak in downstairs underfloir pipework.

 

[Mdljk]

After bleeding it earlier this evening, it was on for a few hours being very slow to get warm.
After turning it off it was refilling for at least 15 minutes until I turned the valve off.

No signs of condensation.
There’s still air moving around quite loudly 20 minutes after turning heating off.
All downstairs pipes are buried in the concrete floor.
Worrying.

With the amount of water you are losing I would expect a carpet to be wet if a pipe within the concrete floor had failed.

 

[Chris12345678]

Could it be a cracked boiler and the water is coming out the flue as steam?

 

[Mdljk]

Could it be a cracked boiler and the water is coming out the flue as steam?

Agree that is my thought if no downstairs leaks found.