Remeha eTwist with Remeha Elga Ace

[rvdbreemen]

Just today got the eTwist that talks to my new Elga Ace work with OTGW. How did I do it, well there is an R-bus to OpenTherm gateway being sold by Remeha. I installed that, then from that gateway I put the OTGW between the gateway and the Elga Ace. And the I restarted the Elga Ace.

And it works just fine. I can now monitor the Elga Ace talking to the eTwist thermostat just fine.

The only thing I needed is that additional gateway. Too bad there is no information on the r-bus itself so far.

[mariaheide]

Hi rvdbreemen,

What OpenTherm gateway are you referring to? I have a Calenta Ace with the R-bus, but when i install the otgw, the etwist doesn't power on anymore.

[rvdbreemen]

So it turns out there is a Remeha R-bus to OpenTherm gateway. It's also known as the eTwist to Opentherm gateway.
You can find it here: Remeha gateway eTwist

It turns the R-bus messages into OpenTherm. And when you reboot your Elga Ace after hooking it up. The Elga Ace switches from R-bus communication, to opentherm. It turns out that it detects this, and also just works with OpenTherm based Thermostats. The gateway was intended for communication with boilers that only understand OpenTherm.

So looking at the technical specification of your Calenta Ace, it looks like it can also be connected to the iSense (which is a known OpenTherm thermostat). So you might be able to do the same and use the R-bus to OpenTherm gateway to convert the R-bus communication to OpenTherm communication. And do the same as I did.

[hvxl]

It looks like Technim sells it for just over half the price compared to Warmteservice. (Also available through bol.com)

[mariaheide]

Thanks so much. I’m gonna order it

[bwbboot]

What are you experiences so far? Is this combination working out for you?

[rvdbreemen]

What are your experiences so far? Is this combination working out for you?

It works great so far. Saving about 100m3 of gas in the last month, of course, more electricity, but I had a solar surplus.

[bwbboot]

Ok great. Works fine here too with this setup eTwist <-> GTW16 <-> OTGW <-> Elga Ace.

I do notice that with a regular frequency the eTwist reported temperature drops to 1c and increases in a few steps back to the correct measured value (pink line).



Do you see this same behaviour?

RU2: Version: 1.93.12
GTW-16 Version 2.2

Edit: I have now switched from OTGW LAN in Domoticz to the MQTT plugin. Let's see if this works more consistant.

[bwbboot]

Ok same behaviour using MQTT. Seems logical since the data is coming from the opentherm protocol.

[rvdbreemen]

I have not monitored it this closly yet. As I am trying to debug my OTGW firmware for a OT decoding thing, I will add my grafana graph to check this for you.