How device triggs the call for heat for central boiler ?

[mrchips83]

This is probably a really noob question but which device triggers the call-for-heat to the boiler: is it the 'hvac-action' of the room VTherm or the underlying TRV in that room? Does it matter?

My instinct was to trigger it via (any of the 5x) VT but I'm thinking of swapping to having any of the 8x underlying TRVs be able to fire the boiler.

Note: I'm using VT over climate with Sonoff TRVZBs underlying

[jmcollin78]

Hello,

Yes this is hvac_action of the underlying device which trigs the central boiler.
If the device don't have any hvac_action then a workaround is done by Vtherm:

1. for switch -> check if the switch is 'on',
2. valve -> check if the valve opening is > 0,
3. climate without hvac_action -> check target temp vs room temp of the device. If > then fake hvac_action is 'on'
4. climate with direct control of the valve (like Sonoff TRVZB) -> check that valve opening percent is > opening_threshold.

Your question is important, I will pin it into the the discussions.

[mrchips83]

Many thanks for clarifying!