HW=state toggle and Opentherm messages

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rickvanderzwet
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HW=state toggle and Opentherm messages

Post by rickvanderzwet »

I have a "Intergas Prestige CW6" boiler and "Honeywell Chronotherm Touch Modulation" setup. On the thermostat I have "Warm tapwater tijdens SLAPEN" (Hot Domestic Water during SLEEP) set to '0' which means IMHO that it should not heat the water in the hot water storage tank during night time. How-ever according the graph - readout of internal intergas sensors - I will do so:
boiler-temperature-resized.png
boiler-temperature-resized.png (90.56 KiB) Viewed 4350 times
I am wondering which type of Opentherm messages to capture if the thermostaat sending a message the boiler to 'not heat the storage tank'. More OTGW focused if I issue HW=0 or HW=1 I would expect to see some Opentherm messages sent to the boiler to enforce this setting, yet this does not seems to be the case. Wondering how this mechanism works.
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Re: HW=state toggle and Opentherm messages

Post by hvxl »

The HW command affects HB1 (DHW enable) in the status message (ID=0). You may have to configure your boiler for this bit to have effect. On my boiler (Remeha Avanta) for example, the P4 setting controls whether the boiler mode is comfort, eco, or controller regulated. The boiler only follows the DHW enable bit when P4 is set to that last one.
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Re: HW=state toggle and Opentherm messages

Post by jgeo »

I'm looking for this feature too, for a Remeha Calenta Ace 40c, controlled with an EvoHome via an OpenthermGateway.
However, how do I make the HW=0 or =1 message being translated into the P4 parameter and have that send to the Remeha heater? In OpenTherm Monitor (https://otgw.tclcode.com/otmonitor.html), I can send HW=0 for example, I get a confirmation, but that probably means that it's only acknowledged by the opentherm gateway, and not by the Remeha? That's at least what I understand from your post. And that I have to program the gateway such that it sends the right command to the Remeha. Indeed, now, when I change HW (to 0, 1, or A), it's confirmed by the opentherm gateway but nothing is changed on the Remaha, when I browse the corresponding menu on it.
Ideally, I'd like to program it to switch from Eco mode to Comfort mode during the day according to a schedule. It seems that I need an eTwist thermostat to do that. Alternatively, I can make Home Assistant do the scheduling, but then I need to be able to set this parameter through the opentherm gateway.
I'd be glad to receive help on either of the two methods, to reach the same goal in the end.
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