How does a eTRV work? Room getting too hot.

[ericmark]

The sun is the main problem, when it shines into living room, the temperature can go really high even in winter.

So there have been a series of attempts to stop living room from getting too hot, the latest is fitting eTRV heads to the two main rooms.

But target 19°C current 21°C measured with eTRV but independent thermostat showing 23.8°C yet the radiator is not cold, it's not as hot as the uncontrolled radiator in the hall, but it still has some heat.

The TRV is a Honeywell think VT15 and the head is a MiHome Energenie link here . I have heard the valve working even though the room has been over temperature for some hours, I have double checked fitting instructions and 2 mm spacer should be fitted and is fitted.

Clearly I could switch off the whole central heating or the lock shield valve and get the radiator cold, but the whole idea of fitting eTRV to the radiators was so I could fit and forget.

I set the programmer on 3 am, off 5 am, on 6 am, off 2:30 am so the boiler would be running at 6 am when the eTRV also calls for heat, the 3 am change over day to day is fixed and first command has to be on, so all on off slots are taken up. I can't set programmer to turn off in the day, and really don't want it to.

So pulling my hair out, how do I keep living room cool?

 

[omega015]

The radiator will still produce heat even after the eTRV has reached its set temp and shut off. On some smart systems they can learn how long it takes to warm up and room and have settings like early shut off and start, in order to maintain set point. Perhaps you could reduce the set point on the eTRV a couple of degrees down knowing its likely to overshoot. Also some of these electronic TRV's have an offset so you can adjust the temp on there to match other thermostats/controllers.

Can you also confirm that the radiator can be completely shut off via the TRV side only (i.e. does not get hot at all)? This will confirm that the TRV/head isn't faulty and still letting water flow.

 

[ericmark]

Turned heating down to 12°C in both rooms, both radiators got cold, but radiator in hall with no TRV stayed hot, so that I think confirms eTRV is correct as far as spaces and shims go. So it does seem there is some "Smart" function which is keeping the radiator warm?

If there is some smart function, then maybe my testing to see if it all works has upset the smart function? So maybe the best idea is to let them alone for a week or so and see if they settle down?