Usefull upgrading my thermostat to Evohome?

Tags: #<Tag:0x00007f326f7dac78> #<Tag:0x00007f326f7da9a8> #<Tag:0x00007f326f7da750>

I have a ‘dump’ thermostat; used nest in the past but not a fan of how it worked back then (i had the v1 in my old house). With Black Friday around the corner i would like to know if the Evohome would be a good fit for my use-case.

To give you an idea of my skill level; I am fairly good at DIY, program and solder my own ESPs, wrote some custom (embedded C) BLE software for it, so connectivity is not really an issue.


  • I don’t have hot water downstairs but a Cooker; the only place which uses hot water is my bathroom.
  • I prefer to have my home automation complement, but not take over stuff.

I am from the Netherlands; have a fairly new boiler (Remeha Calenta from 5yrs)
My boiler does not have an outdoor sensor for the temperature; i am planning to feed the outside temp using a cloud service at first, followed by my own local measurement. Feeding will probably be done via a to be acquired opentherm gateway, in gateway mode, if possible.

My radiators are not yet 'tuned’
I still have to tune my radiators for optimal flow, but i am not sure if that has benefits still if i already plan to use the evohome, can somebody answer this?

I have floor heating
My entire downstairs has floor-heating, i have no radiators there. The pump is attached to a Sonoff R2 and i am planning to use the temp sensors of the IN and OUT of the manifold to see if the pump has to switch on or not (or, if i can get out of Evohome when the ‘zone’ is activatedi would be using that as second backup, in case my temp sensor fails).

  • Would i need a bypass in my system in case i plan to use a valve for downstairs, or…
  • Would you split the 9 loops i have downstairs with the motorized valves from Honeywell as well, and e.g. place multiple BLE sensors which will control the downstairs via the local (RF) api?
  • Is my assumption correct that, whever coupled with an Hce80, i can also connect my floor pump to that system and have it be controlled that way?

I have a wife
My wife would like to have the bathroom heated in the morning;

  • Is my assumption correct that the evohome can configure each knob (if needed) as a seperate zone and that it will know per zone how long the heating time will be? E.g. if i set the bathroom to a temp of 20 degrees at 06:30 that Evohome will ensure (eventually, after learning) that is the case at that point?

I have 3 kids
Knobs will be put in every room upstairs so that my kids can have a warm room when they are old enough to do homework.


  1. Is my home a good candidate for evohome?
  2. Would the above described use-cases be possible in my situation?

I suggest you contact a honeywell installer. Generally I think you could potentially do a lot of that. I have a mix of electric underfloor heating, standard radiators, and in floor convectors and it works great for me. But I have one room that has normal underfloor water heating which it doesn’t work with. I found a list online of installers that had been evohome certified and called one of them and they told me exactly what was and was not possible and installed it all for me. I didn’t think the in floor convectors would be possible but they were (just barely) with their expertise. It’s definitely worth contacting professionals for complex situations like this.

In terms of your wife and kids, it will do everything you want and much more :slight_smile:

I have a python script that automates changing the set points of each room based on the weather outside

The best place to ask the HA-agnostic question is here:

There are some very knowledgeable people on that forum.

1 Like

Hi Gilles,

Let me reply from what I have, and what I have done so far, and what my experience is;

I have a similar house/setup as you:

  • floor heating (downstairs only)
  • opentherm compatible boiler (Vaillant)
  • Cooker in the kitchen (only using warm water for bathroom)
  • I also have a wife and a kid :slight_smile:

In addition, I also have two airconditioning systems (which I also use for heating a couple of months during the winter) for two zones/rooms (living room and bedroom)

I have got the evohome installed for 2 years now and everything is working fine. My setup is a bit different from what the officials Honeywell installers advice (for good reasons I guess: I use an HR92 instead of an official zone devider for my floor heater; I have configured my controller as the temperature sensor for my ‘downstairs’ zone, which also controls the HR92 controller the floor heating-system when there’s heat demand. I do have a ‘bypass’ installed as advised (to prevent flow/boiler issues), which I think is always required/adviced with evohome or similar systems.

Although I have been thinking about an opentherm gateway, I never saw the real advantage of it (yet).

My setup is a bit more advanced and is wife/kid proof, hopefully you will understand after reading all below:
I’m using ‘schedy’, a wonderful ‘app’ which runs inside ‘AppDaemon’ (official home assistant addon). This app provides the ideal flexibility for my purpose; keeping it simple while still allowing manual changing to the system.

To be a bit more detailed about the configuration I created in/with schedy:

  • Use window sensors (zigbee) for 3 rooms controlling the HR92/room/zone; when the window is open, the zone is turned off (in reality set to 5 degrees). When the door is closed, everything is restored to the last setting (or schedule).
  • you can easily allow temporary changes to the temperature and configure them per room; e.g. changing the temperature of a single room by either: the HR92 itself in the room, the controller or via home assistant, they all will be detected as a ‘temporary change’ to the schedule of schedy. After a set amount of time, e.g. 2 or 3 hours, it will go back to the original schedule. In my office it will follow the schedule 1 hour after the temperature change, while in my son’s room it will keep the changed temperature for 2 hours.I think this makes it wife/kid proof…
  • Maybe not relevant for you but it might be interesting:I made input_booleans to enable/disable the schedule per room, but also have the option to disable the schedule for all room (keeping them to the latest (or set) temperature
  • I also have two rooms/zones which I switch between regular heating (boiler/evohome) and airconditioning: an input_select field let’s me choose if I would like to use the regular boiler for heating, or my airconditioning. Depending on the setting, it will control the aircondition or the evohome zone. E.g. when the setting is set to ‘AC’, the temperature setting of the evohome HR92 is turned off (actually set to 14 degrees which basically means off (but will still be there in case the AC fails/stops). This also works the other way around (when set to ‘CV’/boiler, it will turn off the AC and start following the configured schedule I configured for this zone/climate entity in schedy).

So the above is not limited to evohome and can be used with any home assistant compatible zone/heating system, as long as they use the climate-component for control.

Recently I have bought an nanoCUL and using the component of the zxdavb and everything is looking very good; I can see the heat demend per zone/room and also control the temperature. I think I can just replace the climate entity’s with the new ones that are provided by his integration, the only thing is that I need to check how to handle the fact that changes being done by this integation are seen as ‘temporary’ by the controller (removing it’s permanent state), resulting in the controller ‘taking over’ the schedule from this zone instead of ‘schedy’/homeassistant being the master.

If that is sorted, I can remove the cloud integration with evohome and start using it locally.

I’m also Dutch and in case you have questions or would like to know more about my setup or configuration, I’m happy to share it with you, preferably using a PM using our native language.

Hopefully the above helps you in deciding :slight_smile:

1 Like

Thanks, i also have zigbee window sensors (in all rooms which will get an HR92) and have all my automation done in Node-red right now, i wil connect with you in PM indeed :slight_smile: