Thermostat recommendations (UK, old system boiler)

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Would be grateful for recommendations for a smart locally controllable(!) thermostat for UK. The boiler is an old Vaillant VU 142/1E, that’s a system boiler (with a separate water tank).
The system will use Z-Wave so Z-Wave or Wifi control would be preferable.
If the thermostat can separately control DHW it would be really great.

There aren’t a lot of thermostats with Zwave around. I am using MCO Home thermostats and one HeatIt (where the MCO did not fit) thermostat. Both do their job, but the MCO has more options.

DHW (Domestic home water?) seems to be a separate switching entity. Most likely you need some combination of a temperature sensor and a switch for that:

  • either separate thermostat
  • or temperature sensor + e.g. Binary Switch + rule

Actually DHW (Domestic hot water) is controlled now by a thing called “programmer” that allows for setting time intervals (not that it is usable). So probably I should just put some relay switch to control it externally.
However the question of an actual thermostat is still open - zwave or wifi with a local API.
Thank you for MCO and HeatIt recommendations, will check them out.

Look at evohome. Works well in isolation and has a very good openhab plugin. Works fine with old boilers

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I’ve gone for a totally openHAB driven system in my home, which I’ve documented here: My Central Heating Solution using Thermal Actuators

My friend @Rob_Pope has gone for an off-the-shelf system and started the Drayton Wiser Thermostat Binding which allows openHAB to also view and control his heating system.

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I can’t find any support for local control of Evohome thermostat. You mean any specific model?

There is an OH plugin for evohome - Either through PaperUI or there is a newer version tracked here

As for controlling the valves, you can, through OH, set the setpoint of a room. It then tells evohome controller and the evohome controller tells the TRVs for that room.

Advantage is you don’t have to track the temp and turn them off. It feathers them to maintain the temp.

Thread above has lots of information around how to use them too.

Many places to buy them from, I buy from these guys: https://theevohomeshop.co.uk

C

I replaced my boiler unit with one of these, Secure 2 Channel Controller and use two Secure 321 thermostats for manual control. Each radiator has a LC-13 fitted.
I then control the entire system from openHAB, changing temperatures and heating patterns to suit. Using weather information to try and ensure that I only use the heating system when it’s actually required. Although I still haven’t got it working exactly as I want it yet, still a work in progress.

Evohome binding seems to be using cloud to control the thermostat, that is exactly what I’m trying to avoid.
Thermostat valves are great and I’m using them successfully but the boiler still has to be controlled.

Indeed, it is cloud based. I’d prefer not (because I’d rather not) but one thing I do like about it is that, unlike a normal “dumb/smart” trv, using OH and evohome together, OH simply coaxes evohome to do something else.
If Internet drops, evohome still works. If OH crashes, it does not affect the heating. I see these as advantages but agree that it would be better without using their servers…

Read today that Aeotec just announced a radiator thermostat:


Can’t obviously comment yet, but the other Aeotec products have proven to be pretty well-engineered.
I have long been thinking they’re U.S. based but they keep advertising “engineered in DE” since a couple of months. Which in this case is quite important I believe because of the mechanical part that needs to match local existing HVAC setups.

PS: Fibaro has been having one, too: