Nest thermostat or electric TVR's?

ChaunceyGardiner

My experience with Tado and their customer service has been great. It actually made the BBU in my previous flat *more* efficient, by introducing a run-on period for the CH pump. So far, it has never let me down.

Missey_Hissey

Hi I am trying to get my head around TRVs and room thermostats before even considering smart ones.
We have TRVs however they never adjust to the air temperature around them. The radiator is on if the heating is on and off when the boiler is off. I thought they were supposed to adjust water flow and therefore heat based on the air temp? Have I got this completely wrong? Also my room thermostat on the landing upstairs seems not to work as anticipated. Once the temp is reached the heating cuts out and even when the temp drops below that set on the thermostat. It doesn't reacivate the heating either, to do this we have turn up the thermostat. Does anyone know how I can get my system under control AND if I am in the wrong thread can you point me in the right direction. Thanks Missey

System

Missey_Hissey wrote: »

Hi I am trying to get my head around TRVs and room thermostats before even considering smart ones.
We have TRVs however they never adjust to the air temperature around them. The radiator is on if the heating is on and off when the boiler is off. I thought they were supposed to adjust water flow and therefore heat based on the air temp? Have I got this completely wrong? Also my room thermostat on the landing upstairs seems not to work as anticipated. Once the temp is reached the heating cuts out and even when the temp drops below that set on the thermostat. It doesn't reacivate the heating either, to do this we have turn up the thermostat. Does anyone know how I can get my system under control AND if I am in the wrong thread can you point me in the right direction. Thanks Missey

Hi welcome to the forum. TRVs control the temperature in the area that they are in. Some are better at it than others. Have you checked the TRV bodies to see if the pins are free to move?

This is easily done by taking off the TRV head to expose the pin. The pin should then be pressed with a piece of wood or a spoon to check that when pressure is applied to the pin it moves downwards. When the pressure is released, the pin should move upwards under spring pressure. If the pin doesn't move, do not under any circumstances hit it with a hammer. Try a little bit of WD40 and press again.

If you cannot get the pin to move then the pin is most likely jammed due to corrosion or sludge in your CH system and, the very least, the TRV body will need to be changed.

When running a system with TRVs and a thermostat, the thermostat must usually be set to a higher temperature than the room that you want to heat.

The 'advantage' of smart TRVs such as the HR92s with Evohome is that the hall thermostat is irrelevant, The house is divided into zones: we have 12 zones and 21 TRVs. Each zone runs to its own temperature and time schedule set by the user. My hall, for example, is set at 18C. When the temperature drops below 18C, the TRV calls for heat; the valve opens and the boiler comes on. If multiple zones are calling for heat, then the controller works out how long the boiler should fire, and at what gas valve opening, to achieve the desired temperatures with maximum boiler efficiency.

We have seen our gas usage fall by c.20% bit the real advantage is that we have heat in rooms whenever we want it. The system is easily controlled from the central controller, App or individual TRVs. Working out of the door this morning to the shops, a double button press lowered all the zone temperatures by 3C for 3 hours. If I came back, say, in 2 hours, IFTT would have turned the heat back up to its normal schedule.

System

I've had Tado for some time and have been very pleased with the support I've received from the company. It's a 'fit and forget' system and just works. Highly recommended.