Q2 If I use 2 of the starter kits which both have a receiver module will this cause any problems or is it just a matter of wiring the two modules in accordingly?
I have read back again, but can't find out what you mean by modules. I don't have an OpenTherm boiler, so it does not worry me, I do remember however looking at it, and it seemed there was one thermostat type that worked on a master/slave system, so one thermostat connects to boiler OpenTherm and others connect to that master, all being hard-wired to motorised valves, which did not use the micro-switches to turn on boiler.
Seem to remember made by EPH, but only had a quick look at the system, it does seem either hard-wired motorised valves, or electronic TRV heads, no one seems to do both. Which makes sense since an electronic TRV head makes it a motorised valve.
I did look at Tado, but when I looked, they did not seem to impart much information, I know they withdrew their OpenTherm units from the UK market, but have since reintroduced them.
Owners of central heating normally only have one system installed, so can't compare systems very well, and installers once fitted if any good, do not return, so again don't really know how well it has worked. I tried to look into the different makes, and so much is not told to one, and one only finds out after you have bought and fitted the product.
So, only if you get it wrong, does one find out about the failings. And I got it wrong, and so many people will not admit it, when they do get it wrong, so my mistakes.
1) Energenie TRV heads, no option to manually set the heads, has to be set up with a PC or phone, and the anti-hysteresis software is OTT. No indication if pushing the valve pin enough or not.
2) Nest Gen 3 would not connect to Energenie in spite of web saying it would. The geo-fencing turned the heating back on too late, and temperature sensors not released for UK market.
3) eQ-3 TRV heads, will only connect to one phone with bluetooth, and do not show current temperature, only target shown.
4) Kasa (TP-Link/Tapo), batteries do not last as long as the others, and found the wall thermostat they connect to has to be hard-wired, so could not use for a linked system.
So now have Drayton Wiser, which seems to be working well, only problem was TRV head in wife's bedroom was out of range, so need to use a socket adaptor to extend the range.
Some features one never realise exists, until you fit them, Kasa can connect to a remote sensor, eQ-3 can detect an open window, Wiser can also connect to wall thermostat, the eQ-3 tells you if range too long or short, but many of these features you only find out after you have fitted them.
What really messed me up, was hall cools too slowly, I had never considered that could be a problem until Nest was fitted, also looking at what happens in a general power cut, no good having UPS to the boiler, if the thermostat will stop working.
