Please I want to be a little Wiser what is the thermostat for?

[ericmark]

I tried to work out what each system does, however it is hard to find out exactly how they work, with EvoHome it has a HMI (human machine interface) called a thermostat which collects info from all the eTRV's and has a multi-faceted display showing the temperature in each room, so although called a thermostat in fact it is the main hub, it also can use OpenTherm not sure if it can use the Bosch system which like OpenTherm does not switch boiler simply on and off but adjusts flame height.

When I first looked at Wiser and Tado I saw the thermostat and jumped to the conclusion that they measured the temperature in the room fitted, however it may not, but with Wiser instructions comment not to mount where it can get direct sun light makes me think it is a standard thermostat not reading the heat from each TRV. Tado instructions seems to have an "Extension kit" which it seems does use multi-sensors to tell boiler when to fire.

I had originally intended to use Nest, it uses a follow command using IFTTT so either the TRV follows Nest or Nest follows the TRV, since it is IFTTT what is true today may change tomorrow, but when I looked it did not seem that you can set each eTRV head to control rooms independently and for the valves to tell the thermostat when they are not satisfied and require the boiler to run.

I also looked at fan assisted radiators, since I already have one, and how these work, it would seem as with basic TRV they will control the boiler using return water temperature, but unlike the TRV it does not control flow of water, it instead controls fan speed, however they will not work with EvoHome and need a fully fledged building management system, which makes EvoHome sound the cheap option.

Looking at hive I found a list as to which Bosch Worcester boilers it will not work with.

Boilers incompatible with Hive Active Heating

There are some Worcester Intelligent Appliance boilers that aren’t compatible with external heating controls apart from Worcester’s TR2 room thermostat. Hive can’t be installed with these boilers:

GC Number Boiler Model
4710810 Worcester Bosch ICC2 - ZWBR 11-37A
4710811 Worcester Bosch *C*RD 537i
4710812 Worcester Bosch *C*RD 542i
4731156 Worcester Bosch Greenstar HE Plus - ZWBR 7-28A
4731157 Worcester Bosch Greenstar HE Plus - ZWBR 11-35A
4731175 Worcester Bosch *C* Greenstar 30 HE Plus Combi
4731176 Worcester Bosch *C* Greenstar 35 HE Plus L Combi
4731179 Worcester Bosch *C* Greenstar R 30HE Plus
4731180 Worcester Bosch *C* Greenstar R 35HE Plus
4731181 Worcester Bosch *C* Greenstar R 40HE Plus

That does not say much for Hive, I think Hive will possibly work with the boilers by switching them on/off, however the whole idea is not to switch on/off but to adjust flame height. Anyway it does seem Hive for me is a non starter.

I use two Energenie eTRV's in the two main down stairs rooms, and in the hall I have both a thermostat and a standard TRV, not ideal, but after some teething troubles setting up, it does seem to work, up stairs never been a problem, standard TRV's stop the rooms over heating, there is a second programmable thermostat in the kitchen, in the main not used, but if for some reason the house has got cold that thermostat is used to boost the heat, so hall thermostat and TRV are never touched, stop is set to around 20°C so can turn heating down or off with it and return latter to exactly same setting.

I did consider getting EvoHome and using what I already have in mothers house in my house, but it's running well now, so not going to bother. Other than really expensive building management systems I have not found another system to equal EvoHome, however there is nothing to stop one fitting a programmable thermostat and the cheap non wifi eTRV head in every room, I have seen the Terrier i-temp heads for £18 and programmable thermostats at around £25 so would cost around £45 per room, and likely not required upstairs, OK needs hard wiring and not connected to internet or phone, but whole idea is not to have to play, you just come home to a comfortable house every day. It would likely work better than what I have, and would have cost less, and if router goes down it still works.

 

[mattylad]

Eric, you could always go to https://wiser.draytoncontrols.co.uk/contact-us and click on the "email us" button to ask the people that have it on their site.
Tel them to be nice & technical about it
Then paste the reply here.

 

[ericmark]

Eric, you could always go to https://wiser.draytoncontrols.co.uk/contact-us and click on the "email us" button to ask the people that have it on their site.
Tel them to be nice & technical about it
Then paste the reply here.

If I intended to actually install Wiser I would, but the major problem I had has been cured by the eTRV heads. My problem was the sun and bay windows, if the sun shines the bay window catches the sun specially in the winter so living room over heats in morning and sitting room over heats in evening if the sun is shining, the problem was only with down stairs rooms although on bedroom with a bay window that room is not really used much so not a problem. The two Energenie heads have cured the problem once I found a way to control the boiler, this is now the second year with electronic heads fitted and first year with both TRV and thermostat in the hall, that last move was what cured most of the problems, we are told again and again don't fit the thermostat and TRV in the same room, however when I did just that in the hall it gradually cure my problem, I say gradually as it did take some time to fine tune the two devices to work together, however it has now been done and it works.

Idea was the TRV stops the hall reaching the final temperature quickly so allowing other rooms in the house to warm up, but also allows a quick re-heat to a working temperature after the front door is opened, since the hall is between all the rooms if doors are left open the house does cool as heat from other rooms reaches the cooler hall, but if doors are closed it works OK. Not perfect but good enough that it is not worth spending more money to make it better.