Opentherm Gateway

Pieter Blommaert

Hi,
Some time ago, i bought the opentherm to modbus gateway.
I've connected it and basic communication to the gateway seems OK.
My project started longer ago, else i'd probably choosen Neuron. I'm running fhem on RPI. So, the only thing i have at and is the manual of the opentherm gateway.
Before going to the next step of actually connecting the boiler, i'm wondering if anybody has experience with opentherm gateway projects? (Assuming i'm not the only one buying it...) Any suggestions/feedback, esp.

what is the best way to detect that the boiler and the thermostat are online
does it make sense to switch the gateway between monitor and active mode (e.g. in normal condition, i rely on the thermostat, but in case the regular scedule needs to be overruled, i switch to active mode (with the thermostat still connected)
Experience in steering opentherm boilers, do's and dont's...
Neuron/Neuron software has a higher level interface where i could integrate simply and just set measured and expected temperatures? (Can always consider to switch to Neuron, after all including heating control is a rather advanced application)

Thanks,
Pieter

tomas_hora

Hello @Pieter-Blommaert see my replies below:

what is the best way to detect that the boiler and the thermostat are online
- you could use the statistical registers, eg. 2004 and 2006 (or 2104, 2106)
does it make sense to switch the gateway between monitor and active mode (e.g. in normal condition, i rely on the thermostat, but in case the regular scedule needs to be overruled, i switch to active mode (with the thermostat still connected)
- of course, it is only about the coil configuration of the coil whether the gateway is repeating the communication to the boiler from thermostat or no...
Experience in steering opentherm boilers, do's and dont's...
- cannot tell much here, but definitely all pros! :)
Neuron/Neuron software has a higher level interface where i could integrate simply and just set measured and expected temperatures? (Can always consider to switch to Neuron, after all including heating control is a rather advanced
- actually all you need is to set the boiler on or off and set the expected setpoint. The logic of those has to be done in your application. In Mervis there are function block like equithermal curve and time scheduler to help you write your own "thermostat"