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!

  • Vinny_93@lemmy.worldOPEnglish
    1·
    13 hours ago

    English is not my first language and although I can kinda get my point across, technical jargon is a bit of a blind spot. So just to clarify: I have a little vat of say 10 liters connected to the heating pipes. It’s next to the boiler. It contains a rubber membrane in the middle to expand if pressure builds. Is this the type of buffer you’re referring to?

    • philpo@feddit.orgEnglish
      1·
      13 hours ago

      No worries. And while English is not my first language either,I think you were right with the term expansion tank - these are sadly only meant for keeping the pressure stable, not really “buffering”.

      A buffer tank is large (often 500+x l) and well isolated. A bit more modern heating systems use them to, well, basically buffer things- the water in it is heated up (with the actual heating system running under ideal operational parameters and while it takes long its needed less frequently) and then the house getting its heating demand out of that. This is basically the ideal solution for your issue.

      But sadly its often not feasible installation wise - while they are not that expensive they need a lot of room, a floor that can actually bear the weight and of course someone who install them.

      But maybs speak to a professional about it if you own the place - it might be cheaper in the long run if you combine the costs of the alternatives, and these days they have creative solutions sometimes.