Hi all I have an issue with a couple of radiators that I'm hoping I can get some expert eyes on to help diagnose.
I recently drained down the heating system, fitted some TRVs and then refilled and since then have two problem rads. They are both in a single storey extension to the side of the property.
The system is a pretty bog-standard gravity fed type with the cylinder, pump, 2 port valve etc in a first-floor airing cupboard. The two problem rads appear to be fed via a loop near this cupboard. This loop comes into the loft space of the extension, drops down in to the 2 rads and then goes back in to the main house. I've attached a photo to illustrate the connections.
Here's the bit I don't understand. If I open up only the return valve (empty rad, bleed valve shut) on rad B water comes out, if I open up only the feed valve on rad B water does not come out unless I open up both valves on rad A. This seems counter-intuitive to me as the flow to rad B as far as I can see is not dependent on rad A.
I suspect the issue is with an airlock somewhere but don't have the experience or skill set to diagnose this. I've tried attaching a hose to both rads and gently applying mains water pressure to each for a short period of time and I'm reasonable confident that it didn't encounter any blockages.
I should add that I've emptied/refilled the system partially a few times recently as I did a few valves over the course of a few days and after fitting the TRV to rad B there was a supply of hot water flowing through it so I don't think my fitting is the cause.
The feed and return are a mixture of plastic and copper 15mm reducing down to 10mm microbore where they drop down the walls into the rads.
Can anybody help?
I recently drained down the heating system, fitted some TRVs and then refilled and since then have two problem rads. They are both in a single storey extension to the side of the property.
The system is a pretty bog-standard gravity fed type with the cylinder, pump, 2 port valve etc in a first-floor airing cupboard. The two problem rads appear to be fed via a loop near this cupboard. This loop comes into the loft space of the extension, drops down in to the 2 rads and then goes back in to the main house. I've attached a photo to illustrate the connections.
Here's the bit I don't understand. If I open up only the return valve (empty rad, bleed valve shut) on rad B water comes out, if I open up only the feed valve on rad B water does not come out unless I open up both valves on rad A. This seems counter-intuitive to me as the flow to rad B as far as I can see is not dependent on rad A.
I suspect the issue is with an airlock somewhere but don't have the experience or skill set to diagnose this. I've tried attaching a hose to both rads and gently applying mains water pressure to each for a short period of time and I'm reasonable confident that it didn't encounter any blockages.
I should add that I've emptied/refilled the system partially a few times recently as I did a few valves over the course of a few days and after fitting the TRV to rad B there was a supply of hot water flowing through it so I don't think my fitting is the cause.
The feed and return are a mixture of plastic and copper 15mm reducing down to 10mm microbore where they drop down the walls into the rads.
Can anybody help?
