Hello. I have a problem with 2 rads that are very close to the level of the expansion tank. After any maintenance or a drain-down they both require bleeding many times over a period of weeks. I have to drain down between Christmas and new year and am considering fitting automatic valves to these rads. Any comments on the usefulness of such valves and also any recommendations of particular valves to use or avoid?
Many thanks,
Nick.
My thoughts are - don't bother - just leave a key on the radiators and do it when you think about it. Automatics tend to weep in my opinion. If you know you have a problem then you will deal with it.
I had what was described as an automatic in an old rad and it started to leak so as I intended replacing the rad soon I just plugged a towel beneath the leak which was slight ..got up one morning and found the boiler lights flashing and the pressure way down ...I found what had been a slight leak had turned in to a spewing of water out the bleed valve .....after sorting things I found the bleed valve consisted of it's innards being what looked like a bunch of small paper discs which apprently swell up ...these ones had disintegrated ...hence the leak . Never again ..
Contrary to the experiences of other posters I have used these in two houses for going on 20 years and have no issues with them at all. In the current house there's one in the airing cupboard that appears to be part of the original 1988 installation and one on a radiator that I put in about 12 years ago.
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Have you got a picture or a maker's name for those?
Cic.
No picture. The ones I bought were no-name ones from B&Q.
Check if the boiler can be fed off a one pipe feed and expansion - needs a high temp limit stat. One of these can be fitted on the flow pipe right at the boiler and cuts out the burner when activated. Set to 90-95C. Best do this. Best fit an air removing vessel, about £10-12 as well. Flow in, flow out, 22mm out of top to F&E tank.
Auto air vents are for filling purposes only and should not be left open.
They must be screwed up after the air is out - never left open.
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