TRVs versus Room Thermostat
- Thread starter wbjimmy
- Start date
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FFS why has this thread turned into such a complicated one
OP your plumber is an idiot
to comply with everything & save energy all you needed to do was exactly what you have except the hall rad (where the room stat is) shouldn't have a trv fitted, so either remove the trv from the hall & fit a normal locksheild rad valve or remove the head of the trv.
it really is that simple
OP your plumber is an idiot
to comply with everything & save energy all you needed to do was exactly what you have except the hall rad (where the room stat is) shouldn't have a trv fitted, so either remove the trv from the hall & fit a normal locksheild rad valve or remove the head of the trv.
it really is that simple
Just returned from hols and caught up with the discussion. When I left on hols the temp was 14 degrees. Today it's 32! SWMBO has finally stopped complaining about being too cold and discussion about TRVs and room stats now seems somehow irrelevant - Im tempted to start a new one on the merits of portable AC units instead! However, I'm really grateful for all the advice. In summary this is my take on all the advice I have received:
- There is general agreement that my plumber is a numpty.
- The simplest and cheapest solution may be to remove the TRV head from the hall rad ( Q. and slightly close the lockshield valve to ensure it doesn't warm up too quickly?)
- if SWMBO still finds it too cold in the lounge when the hall stat reaches required temp for the hall then consider replacing wired stat with wireless stat located in lounge.
- Use existing 4 wire (including earth) at hall stat to connect wireless receiver recognising this will not provide a permanent live feed and will require "handshake" with room stat every time programmer switches on CH (Q. Why might this be unsafe/undesirable?).
- Alternatively, site receiver next to wiring centre and existing programmer with dedicated permanent live feed ( Q. Do I just take a spur off the mains circuit to provide this?)
Grateful for your thoughts on this summary. One final question though. Why did my numpty plumber install an auto by- pass valve when he fitted the TRVs and do I still need to use it (its gate valved) if I remove the TRV head in the hall?
- There is general agreement that my plumber is a numpty.
- The simplest and cheapest solution may be to remove the TRV head from the hall rad ( Q. and slightly close the lockshield valve to ensure it doesn't warm up too quickly?)
- if SWMBO still finds it too cold in the lounge when the hall stat reaches required temp for the hall then consider replacing wired stat with wireless stat located in lounge.
- Use existing 4 wire (including earth) at hall stat to connect wireless receiver recognising this will not provide a permanent live feed and will require "handshake" with room stat every time programmer switches on CH (Q. Why might this be unsafe/undesirable?).
- Alternatively, site receiver next to wiring centre and existing programmer with dedicated permanent live feed ( Q. Do I just take a spur off the mains circuit to provide this?)
Grateful for your thoughts on this summary. One final question though. Why did my numpty plumber install an auto by- pass valve when he fitted the TRVs and do I still need to use it (its gate valved) if I remove the TRV head in the hall?
Yes, you need to balance the system so the hall is a little slower than the other rooms to warm up - that way the hall stat won't turn the heating off prematurely.
No, in the wiring centre should be all the circuits you need, all powered from the one supply which is essential for safety.
At the TRVs close down, the flow through the rads reduces. Up to a point this is OK (but makes the system noisy), but after that the flow rate through the boiler is insufficient and it may shut down - or worse may be unable to control temperature and start "kettling".* If correctly set, the ABV will start to open when the differential pressure reaches a certain level - and allow a bypass of flow to keep the boiler happy.
Yes, you probably need to keep it as the flow rate through the one hall rad will almost certainly be too low once you've throttled it down to balance the system.
* Kettling is where the boiler overheats the water in the heat exchanger and boil it. Depending on the design of the boiler and how bad it it, it may just whistle, or it may start doing some quite alarming banging.
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Thanks to all who have contributed to this thread and to SimonH2 for his v helpful explanation of why I need a by-pass valve. I will remove the TRV in the hall and see how it goes. If domestic strife continues I will have a go at mounting a wireless stat receiver next to my programmer in the airing cupboard. But given the maze of wiring in the wiring centre I might just chicken out and get a sparky in to wire it up! Thanks again.
Kettling is caused by deposits of debris or limescale causing hotspots which causes localised boiling. Not necessarily the whole heat exchanger, may be just hot-spots.
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