Smart TRV question on new setup

thomo

Hi,

Thinking of chanign my CH setup to a Tado.

Setup:

Ideal combi boiler - dual zone CH valves for seperate upstairs and downstairs.

Downstairs controlled by a wired ESI thermostat in the hallway - rad in the hallway has no TRV on it, rest of ground floor rads do

Upstairs controlled by a wired ESI thermostat in master bedroom - rad in that room has no TRV on it, rest of upstairs rooms do except towel rail in main bathroom

Downstairs stat set to 18, Upstairs stat set to 17

Hall way stat set at 18 currently which gets the living room comfortable and the dining room and downstairs loo enough heat to take the chill out the air and keep the damp and mould away. Id like the living room warmer than it gets, but turn the stat up to 19 and the hallway is freezing so takes ages to get there and uses more gas to keep in there.

Upstairs is always cold but again is just enough heat to keep the damp out the bathrooms, i dont want to heat the bedrooms all day for the sake of as nobody is up there, and when people are up there they are sleeping so have duvet's!

Scenario:

If i replace both current ESI wired stats with 2 wired tado stats - everything carries on normally as it does now.

If i then add in the smart TRV's:

2 in living room, 1 in dining room, 1 in downstairs toilet

Question:

If i set the smart TRV in the dining room to say 17 and it dropped below so called for heat on its own, but the temp in the hallway was above the wired stat set temp - would that also heat up the hallway rad as it doesnt have a TRV on it, meaning that the hallway will get even warmer than set on its wired stat - thus meaning the living room would wait even longer for heat as the hallway would have to drop below its set temp.

Or would the living room also call for heat when they fell below their set temps, even if the main stat in the hallway was still above its set temp.

If so apart from heating the hallway up what is the point in the wired stat at all when the other room smart TRV's would basically over-ride it all the time. And if the other room are at temp, i dont want to be heating just the hallway uo for the sake of it, but unless i put a TRV on it then that rads always going to be on when 1 of the other rooms calls for heat.

Put a TRV on the hallway rad and the wired stat becomes even more useless

Or have i fundamentally got this all wrong :)

Thanks in advance

wateroakley

In principle, you’ve got it worked out. Some tweaks … When you have multiple TRVs and/or room stats in a room, one is set as the measuring device. Room stats measure temperature more accurately than TRVs. Without a TRV in the hall (or master bedroom) that room rad will heat up when other rooms on that circuit call for heat. With TRVs everywhere, room temperatures can be better controlled for comfort. You may be best to get your plumber/engineer to add a trv valve or two. Check with your plumber/engineer if your boiler needs an external bypass.

BTW, it’s a common new build idea to put the upstairs circuit room stat in the master bedroom. Our non-Tado rellie has that dumb idea in their new build. The result is a cold nursery for the very young offspring.