air only in 1 radiator

[XMT]

Hi All,

Struggling with air in the CH system. There seems to be air in 1 radiator only! no idea why. When this towel rad is turned off there is no air in the rest of the system. I would assume if the air was coming from another part of the system then it would go to other towel rad but it doesnt.

Why would 1 towel rad get air only?

I have a gravity fed system with a hot water cylinder in the airing cupboard etc

[geeks]

What happens if you bleed it?

[XMT]

geeks said:

What happens if you bleed it?

air comes out lol.
but its quite a bit of air! having to do it daily

Edited by XMT on Tuesday 28th November 12:26

[Dave_ST220]

My mums system was acting like this, same rad all the time (bathroom). For some reason the BG muppets had the pump on max setting (only a small system!) since dropping the speed down & bleeding it's been fine.

[XMT]

Dave_ST220 said:

My mums system was acting like this, same rad all the time (bathroom). For some reason the BG muppets had the pump on max setting (only a small system!) since dropping the speed down & bleeding it's been fine.

Thanks for the advise. I tried this too. I had it at 2 and it was still doing it. Its a house with 15 radiators so 2 should be the minimum but for today I am testing setting 1 to see if it helps.

I am suspecting the piping for that particular rad might have a pin hole in it somewhere bringing air in but not letting water out or its plumbed incorrected. its a radiator closest to the CH pump and hot water cylinder.

[Dave_ST220]

My mums was closest to the cylinder & pump too Is there a pipe higher than the rad in the cylinder cupboard with a bleed screw? Air goes to the highest point which is what that is supposed to do. Are you bleeding when hot/pump running or cold?

[XMT]

Dave_ST220 said:

My mums was closest to the cylinder & pump too Is there a pipe higher than the rad in the cylinder cupboard with a bleed screw? Air goes to the highest point which is what that is supposed to do. Are you bleeding when hot/pump running or cold?

I will take a picture of the airing cupboard with the pipe work because I sort of suspect the way the raditor pipework has been done is causing the issue. you can see the pipework go into the bathroom from the airing cupboard.

Ps. I tried bleeding with running at hot and cold, regardless air is always there.

ill get the pic up about 6pm. Grateful for your help

[guindilias]

An automatic air vent is another option, again above the highest point of the towel radiator. Summat like this (Screwfix)

https://www.screwfix.com/p/bottle-air-vent-15mm/34...

[BlackZeD]

Sounds like air is getting in through a joint when it cools.
Give the nuts a tighten when its hot, on the towel rad.

[davebem]

Ive got this problem too, but instead its a combi boiler on an old thick single pipe system feeding 9 big radiators and a towel radiator. The towel radiator which is the 1st one in the system and also the highest has to be bled of air weekly. Nobody can get to the bottom of it, but I guess when the combi gives up we will need all new dual piping (and valves) anyway.

[XMT]

BlackZeD said:

Sounds like air is getting in through a joint when it cools.
Give the nuts a tighten when its hot, on the towel rad.

This is what I strongly suspect: especially as the chrome pipes need to be scratched/filed down to allow a grip from the fixing nuts etc. I suspect one of them is loose and it's allowing air in.

However I will first check the pump on speed 1, see it is it for a couple of days and take it from there. Nightmare these systems!

[Dave_ST220]

One other thought. May not be air at all. Could be gas from corrosion!

[King Herald]

Our bathroom rad is always the one to get air in. Quite common apparently.

It won’t be a leak, or water would dribble out, even when turned off. The head of water from the tank is plenty to stop the system ‘sucking’ air in even without the pump running.

I’d say it is gas from corrosion. Do you have the proper additive in?

[XMT]

Well I tried speed 1 and even though I thought it maybe reduced the amount of air I can't be sure.

Also I don't think speed 1 works too well it takes too long for the downstairs rad to warm up to my liking.

The system had new water added 3 weeks ago once all rads were fully fitted. Plumber was supposed to come back and add additive but didn't, he tells me this after I ask him 2 days go. I have ordered some and it's coming today.

My question is how much gas would corrosion give off if it is that?

Image below is from just under HW cylinder.

Edited by XMT on Wednesday 29th November 20:15

[King Herald]

I would imagine the inside of every radiator is oxidising with the new fresh oxygen rich water it, so lots of gas coming off.

We used it get lots of gas and noise off ours, BG Homecare Guy told us we HAD to have a pressure flush and lot of new copper pipes fitted.....£800 worth....


.....local plumber told me to just add a £20 bottle of goop.....and a day later we had silent central heating. Once a year I added another bottle and all was good.

[PDP76]

The home service contract providers are terrible for dropping the system down then refilling with no inhibitor. Keep an eye on them and ask them to do it. Or better still for peace of mind, keep your own record and add inhibitor yourself yearly.
Dropping down and refilling and adding inhibitor is pretty easy.
I normally just drop a litre or so out of the system and add the concentrate inhibitor into that rad, refill, bleed and run.
System will be better for it.

[Bikesalot]

King Herald said:

.....local plumber told me to just add a £20 bottle of goop.....and a day later we had silent central heating. Once a year I added another bottle and all was good.

I had a kettling boiler and some cold spots on some rads - added a £10 bottle of calmchem central heating cleanser - quiet boiler and no cold spots after two days.

[FredAstaire]

I've been bleeding my radiators a lot recently - funnily enough, following a visit from BG to replace the motorised valve.

I've got a sealed system - is there anything I need to consider before adding some inhibitor via a towel rail? e.g - is there particular inhibitor I need?

[Dave_ST220]

Just get the no nonsense stuff from screwfix