Central Heating

Radiators not warming downstairs (system is open vent with a y plan valve)

Anonymous user 14/03/2024 - 2.34 PM

I am having trouble with my heating and its a complete head scratcher. The system is an open vent with a y plan valve. Water tank and CH tank in loft. Hot water tank in airing cupboard in the bedroom and boiler in the kitchen. There is a thermostat in the hall and 3 out of 6 rads have a tvr fitted (lounge and both beds). The kitchen, hall and bathroom rads don't. After not needing the heating on for a while we switched on a few weeks ago to find that the rads downstairs did not heat up at all! I checked the pump and decided to replace it. Once replaced I turned the CH (only) on. Wow! The house got really toasty! Problem solved I thought. The following morning when the HW and CH turned on, only the hot water got warm. Not as hot as it used to be, but the rads downstairs don't come on now. I did a little online checking and decided to take a look at the motorised valve. This is working as it should with the pipes going to the rads and water tank running hot. The switch is loose and floppy when the power is on. With the power off there is resistance when switching to manual then springs back to auto. Still with both HW and CH on I get nothing downstairs. A little more trouble shooting online and I thought that because the programmer lost the function to control the HW & CH independently, then maybe that could be faulty. That was changed last night and I am still not getting anything from the rads downstairs when both are on. If I switch just the CH on everything warms up as it should. I am now out of ideas and would very much appreciate some advice. Many Thanks Reply to Evergreen. Thanks for your comment. When only the heating is all rads get warm. When both heating and water are on the rads dont warm up much, mainly upstairs ones. The bedrooms and lounge have trvs the rest don't. I will try your suggestion and let you know. When shutting the rads off, do I leave the trvs on? (they are all set to 5 at present). I have balanced the rads. Most of them have the valves only turned about a quarter to half turn. Thanks