Gurgling and air in central heating

[jim843]

@John.g have isolated towel rail and will rely on the electric element for a bit.

I checked the rad in my sons room and there was a little bit of air in that one too.

I also completely turned off rad in the other bedroom after someone said the joint looked like a bodge job.

Will check back in a few days.

 

[jim843]

Can shut off that towel rad "permanently" for a few days and see does the air appear somewhere else and if noise subsides?.

@John.g I isolated the towel rail for 3 days. Switched on the electric element.

On day 1 there was a tiny bit of air in the rad in my sons room. No air in any other rad.

On day 2 and day 3 there was no air in any rad.

On day 3 I checked the towel rail. There was a bit of air in there but not loads.

I opened up the rad valves last night. I checked this morning and there was a bit of air in it again.

So I’m thinking there’s two possibilities:

1. The towel rad valves are cheap/somehow letting in air? This needs refitting.

2. The pipe work before the towel rad is filling up with air.

Which is more likely? With the rad shut off, if there was air getting in elsewhere in the system, would you expect the air to end up in another rad?

 

[John.g]

Wouldn't be surprised at a bit of air in towel rad with element on.
Would suggest repeating test.
isolate the towel rail with the electric element off and the bodge rad off for a few days.
if no air, open up the bodge rad and if still no air after a few more days reopen the towel rail. If you then get air its the towel rail that's the culprit.

 

[jim843]

Wouldn't be surprised at a bit of air in towel rad with element on.
Would suggest repeating test.
isolate the towel rail with the electric element off and the bodge rad off for a few days.
if no air, open up the bodge rad and if still no air after a few more days reopen the towel rail. If you then get air its the towel rail that's the culprit.

Ok, just so I’m clear…

Isolate rad via valves. Leave heating element off. Leave rad for a few days.

After a few days, check if there’s air in the rad.

After a few more days, reconnect rad via valves. If there’s air then the radiator is causing air?

 

[Deleted member 123817]

OK, maybe slightly different method but either way you want to establish if either or both the towel rail &/or the sons rad are the cause of the air.
Shut towel rail isolating valves off both sides then open air vent to ensure valves are tight and not passing. Leave or shut off the electric heating element. After a few days if no air anywhere then towel rail is the culprit, If still getting air shut off the sons rad both sides, if still getting air then problem probebly caused by weeping pipes?

 

[jim843]

OK, maybe slightly different method but either way you want to establish if either or both the towel rail &/or the sons rad are the cause of the air.
Shut towel rail isolating valves off both sides then open air vent to ensure valves are tight and not passing. Leave or shut off the electric heating element. After a few days if no air anywhere then towel rail is the culprit, If still getting air shut off the sons rad both sides, if still getting air then problem probebly caused by weeping pipes?

Ok, I’ve just switched off the isolating valves on the rad. I bled the radiator for quite a while and there was a lot of water then air then water then air. It took a few mins for that to finally loose pressure entirely.

I took the bleed valve off entirely and topped up the rad with 300ml of cold water.

I then opened the isolation valve for a split second to re pressurise the rad. I bled it again for a few seconds. I think this means the rad is now (in theory) without air!

Are you suggesting leaving the air vent entirely open?

I don’t know what you mean by “sons” rad?

 

[John.g]

If you mean the Towel Rail (your description) rad then yes leave the air vent open. and test system again for a few days.

"I also completely turned off rad in the other bedroom after someone said the joint looked like a bodge job." thought this was your son's rad, if you are still getting air somewhere with the suggested test then isolate this rad as well and test for another few days, ie with both towel rail rad and the bodge rad isolated.

I'm not sure if water still seeps from the pipes with the bodge rad isolated? but if so and if you are still getting air after the second test then this possibly the reason?.

 

[jim843]

If you mean the Towel Rail (your description) rad then yes leave the air vent open. and test system again for a few days.

"I also completely turned off rad in the other bedroom after someone said the joint looked like a bodge job." thought this was your son's rad, if you are still getting air somewhere with the suggested test then isolate this rad as well and test for another few days, ie with both towel rail rad and the bodge rad isolated.

I'm not sure if water still seeps from the pipes with the bodge rad isolated? but if so and if you are still getting air after the second test then this possibly the reason?.

The “bodge” rad has been isolated for over a week. I haven’t looked at as the room is fairly warm.

The radiator in my sons room is connected and heating fine.

I’ve opened the air vent on the towel rail.

 

[jim843]

@John.g The bathroom towel rail has been isolated for a week.

Before turning on the bathroom towel rail, I bled all the rads today for between 1-2 mins to be sure that there was no air.

Only one rad had a little bit of air in. On the same floor as the towel rail. It wasn't just straight air but a mix of air/water. Maybe 25seconds worth, didn't seem to be that much air. Certainly a hell of a lot less than we had in the towel rail. All other rads were fine. For reference I have 9 rads in the house.

I've put some inhibitor in the system and opened the towel rail.

I'll give it a few days and check the towel rail? If there's air in the towel rail then it's somehow pulling in air?

 

[John.g]

Looks like that but really you shouldn't be getting any air anywhere now IF that is/was the problem, did you or someone say that air might be getting in where the electric heating element is screwed into it?, you might be able to rejoint that.