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Honeywell Lyric T6 settings OTGW

PostPosted: Tue Dec 11, 2018 8:47 pm
by Sky
I have recently installed a new OTGW module.
The connected boiler is a Remeha Calenta Ace.
The thermostat is a Honeywell Lyric T6 (the wired version).

The startup with the boiler was flawless and worked out of the box.
The startup with the thermostat was not.
I will post my experience, hoping that my mistakes are helping someone else.

I ran the OTGW with the diagnose software and noticed that test 2 (voltage levels thermostat) showed three voltage levels.
Thermostat: 0.79, 1.27, 2.05
The middle value of 1,27 Volt corresponds to roughly 10 Volts from the thermostat.
This is odd and does not fit within the Opentherm specs.
Possibly Honeywell added some functionality that is not meant for OT communication, however I speculating this.

Anyway, with the default reference voltage at 1.25 Volt this caused malfunctioning communication.
Results of test 5 (time delays) were also unrealistic (values around 1-2 msec)
After increasing reference voltage by one step (1.46 Volt) the communication started working.

In my case I needed a week to find this out as I was first looking in other directions.
I also blew up all of my IC's due to plain stupidity.

Re: Honeywell Lyric T6 settings OTGW

PostPosted: Sat Feb 23, 2019 10:18 am
by Jensen
Can you tell us witch OTGW you are using and how to connect to the Calenta ACE please?

Re: Honeywell Lyric T6 settings OTGW

PostPosted: Sat Mar 30, 2019 9:23 pm
by Sky
Hi Jens,

are you experiencing trouble with the combination OTGW/Remeha calenta ACE ?
That was the part that worked out of the box in my case.
I did not connect the thermostat to the OTGW at first, only the boiler.
OTGW started sending messages over the serial interface directly.

Only after connecting the Thermostat I started to have problems.