Air in rads

Germag

I have a 2 story house with 13 rads, one of which collects air and has to be bled every month. This is a towel rail on the ground floor, back to back (wall in between) with another towel rail the same size. The 1st rail is 2nd on the line and is the only rad ever to have to be bled. There is no sign of leaks anywhere and the system was installed 5 years ago. The system is open 2 pipe, with expandsion tack in the attic. Help would be appreicated.

Wearb

What is your heating source(s)? Do you run the system sometimes with a lot of the rads or zones turned off? Any new additions to the system? Do you know if it has correct amount of inhibitor in the system?

On a system like this, the best way to check for leaks is to tie up the ballcock on the expansion tank (you may have a valve to stop this supply) when system is cold and check it (daily to make sure it doesn't go empty) after about a week (when cold) to see if the level has fallen.

Also check to see if there is water coming out of the vent pipe when you have the least amount of zones on.

youtheman

I have 2 towel radiators in my house, and they are the 'high point' in the system upstairs (open system). And they are always getting air in them. So I just removed the 1/2" blank from one end of the radiator, and screwed in one of those automatic bleed valves http://www.mrcentralheating.co.uk/honeywell-auto-air-vent-ea122?gclid=CMHKtOGIgsICFS3HtAod2XUAiQ&zenid=tgicd22im28ommlcobsp0bcvm6 . Not the prettiest, but saves me having to continually bleed the system.

Dtp1979

youtheman wrote: »

I have 2 towel radiators in my house, and they are the 'high point' in the system upstairs (open system). And they are always getting air in them. So I just removed the 1/2" blank from one end of the radiator, and screwed in one of those automatic bleed valves http://www.mrcentralheating.co.uk/honeywell-auto-air-vent-ea122?gclid=CMHKtOGIgsICFS3HtAod2XUAiQ&zenid=tgicd22im28ommlcobsp0bcvm6 . Not the prettiest, but saves me having to continually bleed the system.

That's only putting off the problem.

SmallBalls

youtheman wrote: »

I have 2 towel radiators in my house, and they are the 'high point' in the system upstairs (open system). And they are always getting air in them. So I just removed the 1/2" blank from one end of the radiator, and screwed in one of those automatic bleed valves http://www.mrcentralheating.co.uk/honeywell-auto-air-vent-ea122?gclid=CMHKtOGIgsICFS3HtAod2XUAiQ&zenid=tgicd22im28ommlcobsp0bcvm6 . Not the prettiest, but saves me having to continually bleed the system.

There's a reason why your getting air in these rads, putting an aav on them only masks the problem.

Germag

Sorry for not getting back sooner. All pipework is above ground, so can easily be checked for leaks. The towel rail in question is on the ground floor. There are 2 heat sources, oil fired boiler and solid fuel fire, both can be on at the same time. The solid fuel fire heats 4 rads and hot water tank, all upstairs and the oil heats everything. I have no great problem with this, just puzzeled as to why this rail should have the air and no other. I would have thought that the air should be in rads at the highest point on the system but then what would I know.

Dtp1979

Germag wrote: »

Sorry for not getting back sooner. All pipework is above ground, so can easily be checked for leaks. The towel rail in question is on the ground floor. There are 2 heat sources, oil fired boiler and solid fuel fire, both can be on at the same time. The solid fuel fire heats 4 rads and hot water tank, all upstairs and the oil heats everything. I have no great problem with this, just puzzeled as to why this rail should have the air and no other. I would have thought that the air should be in rads at the highest point on the system but then what would I know.

The dual system could be piped wrong and pitching. This would cause air in the rads. There could also be corrosion issues leading to a build up of hydrogen gas gathering in your rad.