"Set Square" wrote in message
...
In an earlier contribution to this discussion,
dennis@home wrote:


If you have TRVs on all the radiators then all you need to know is if
the conservatory needs heat.
If it does you fire the boiler.
You do this by putting a second stat in parallel with the room stat.
In fact you could have several stats if the layout needs it.

I think its a bodge but TRVs are a bodge anyway.

Yes, but don't forget that the room in the house where the original room
stat is located *won't* (or *shouldn't* at any rate!) have a TRV on its
radiator. Using your system, that rad will get hot when the boiler fires
to
heat the conservatory - even if the rest don't.

I did say TRV on all.


Also - unless the conservatory rad has a TRV - which will fight with its
room stat if it *does* - the conservatory will get heated when the rest of
the house is being heated, even if not required.

The TRV needs to be set slightly higher than the room stat.


Positive zoning using motorised valve(s) would be far better - and would
almost certainly be *required* if the setup needs to meet current building
regs.

I agree, zone valves with end switches is easy and how I have done mine.
However it was designed properly not some bodge dreamed up by a committee
like TRVs were.

Your solution is a recipe for heating *everything* whenever *anything*
needs heating!

No it will only heat if one of the stats calls for heat just like most
systems with TRVs.