Towel rail keeps filling with air...

Towel rail keeps filling with air...

Author
Discussion

NikB

Original Poster:

1,834 posts

272 months

Friday 11th September 2009
quotequote all
One of my towel rails seems to be filling constantly with air. I have bled it several times and it works for a while then starts getting cold on the higher part as it fills with air. The odd thing is there is a towel rail in another bathroom on the same floor that is a lot taller than this one which is OK. Any ideas?

ThatPhilBrettGuy

11,809 posts

247 months

Friday 11th September 2009
quotequote all
Probably the way the water flows. Gets to this one first. Really question is how's the air getting into the system in the first place....

Ricky_M

6,618 posts

226 months

Sunday 13th September 2009
quotequote all
Sometimes if the open vent and fill are installed in the wrong postion on the heating pipework, the system operates mostly under negative pressure. If you have a radiator valve that is not fully tight, it will draw air in through it. Check the valve connections on your valves. Also check you have enough water in your f+e cistern in the loft.

Whenever I go to a house with air re-appearing in the rads, I connect an automatic air vent to a rad and leave it for a week.

Gingerbread Man

9,173 posts

220 months

Sunday 13th September 2009
quotequote all
Air in a system always seems to collect in one rad. You have to ask how it is getting into the system in the first place.

Pump on the return or flow? Have you an open (header tank) or a closed (expansion vessel) system? If open - it might be pulling air in through the open vent in the header tank. You can extend this into the water, so any sucking will suck water instead of air.

Hard one to guess at.


Arthur Jackson

2,111 posts

237 months

Sunday 13th September 2009
quotequote all
It's probably either making hydrogen due to lots of sludge, or more likely it's pumping over into the header tank and the water is being re-oxygenated (also leading to hydrogen). Check the vent isn't running ito the tank. You should almost NEVER see water coming out of that vent except in extreme cases. The expansion should be dealt with in the pipework, so long as the system has been properly designed.

Gingerbread Man

9,173 posts

220 months

Sunday 13th September 2009
quotequote all
Arthur Jackson said:
It's probably either making hydrogen due to lots of sludge, or more likely it's pumping over into the header tank and the water is being re-oxygenated (also leading to hydrogen). Check the vent isn't running ito the tank. You should almost NEVER see water coming out of that vent except in extreme cases. The expansion should be dealt with in the pipework, so long as the system has been properly designed.
If it is hydrogen, when bleeding the air/ hydrogen out, see if it lights with a match. If so, it's hydrogen coming out.

Buy some inhibitor and dilute into the system.