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!

  • Francisco@lemmy.worldEnglish
    1·
    3 days ago

    Having seen this webpage https://www.draytoncontrols.co.uk/news/opentherm-explained , which kind of modulation do you have? Long boiler runs are not always bad.

    Also, are you able to use the living room TRVs to restrict the livingroom radiators heat output while keeping what you have set as the main setpoint, in the use case you detailed. That would avoid having the main thermostat triggered off too soon.

    • Vinny_93@lemmy.worldOPEnglish
      1·
      3 days ago

      There is only one TRV in the living room because the other valves are not thermostatic. I would need to replace those to achieve what you describe. But then I think that’s not the way to go because it could damage the pump from what I hear.

      The boiler is a Remeha Tzerra Ace which supports Opentherm with modulation. It’s also wired on the opentherm contacts and the T6 supports it.