TL;DR: How do I make the thermostat send a ‘heat’ request to the boiler without making the boiler use way too much gas?

Hi all,

I have a question about automating central heating. My current setup:

Ground floor:

  • Main thermostat linked to boiler (Honeywell T6 on WiFi through Honeywell integration)
  • One radiator with Sonoff TRV-ZB, zigbee
  • Three radiators with non-smart knobs that are usually open
  • The main room has a Sonoff Presence sensor

First floor:

  • Three rooms that can be occupied with Sonoff TRV-ZBs.
  • Two of three rooms have Sonoff Presence sensors

All rooms that can be heated smartly are controlled through a blueprint once shared here called ‘Advanced heating control V5’.

I have a helper called ‘Comfort Temp’ which is a slider that controls the setpoint on the main thermostat and the TRV of an occupied room.

So the obvious question is: is there any good way to get the main thermostat to send a heating request to the boiler?

I’ve seen something about a WiFi module that you can put in between the main thermostat and the boiler that offers more control (Nodo OpenTherm Gateway, OTGW). Does anyone have experience with this? Or do I solve this with more TRVs on my ground floor? I’ve heard about central heating systems not enjoying a fully thermostatic valved circuit. More TRVs also means I have to replace the valves on a couple of radiators.

Any advice would be greatly appreciated!

  • realitista@lemmus.orgEnglish
    4·
    4 days ago

    I use Honeywell Evohome which controls both the rooms via TRV and the boiler via standard thermostat control. Either on/off in the case of no open therm or on off and temperature modulation in the case of open therm (which I upgraded my boiler to when it broke). It works very well and has good homeassistant integration including a local one.

    • Vinny_93@lemmy.worldOPEnglish
      4·
      4 days ago

      I considered this when getting my TRVs but I prefer it to be Zigbee. Also I’m not planning to substitute all my current TRVs for different ones, that’ll be a costly operation. I think if I was looking for a closed (ie one manufacturer) system I might lean towards Tado or maybe PlugWise.

      Thanks for the suggestion!

      • Chris@feddit.ukEnglish
        2·
        4 days ago

        Tado does temperature modulation through OpenTherm or manufacturer specific EMS. In the UK the older V3 models didn’t support it though (for reasons I didn’t fully comprehend, ended up getting an Extension Kit off eBay which does support it), I think Tado X is less of a minefield in that department.