Nodo OTGW and Vitodens 100

[frazell]

All,

I'm looking for some information on the Nodo OTGW and interaction with a Viesmann Vitodens 100 boiler.

This particular boiler does not return the correct values for boiler max CHW temperature, effectively locking it at 80deg C. The boiler does not provide any interface to be able to set or adjust it.

On another forum one of the members established that using a Nodo OTGW you can intercept the boiler max CHW temperature request (command #57) and send on a new setpoint to the thermostat using the gateway. This was a few years ago and the member found that he had to modify the source code to get this to work as the command did not appear to be forwarded.

I'm mindful that the gateway software has probably moved on a little since 2019 so wondered if sending a modified request to the thermostat is now possible without modifying the source code.

Thanks in advance for any assistance.

Frazell

[hvxl]

Your description is extremely vague. But if you are wondering what has changed in the firmware since 2019, a good place to start looking is the change log. That says there was a change in firmware versions 5.5 and 6.2 for the vitodens: "Init messages that have been marked as unknown are skipped. This allows using the UI=49 command as a work-around for buggy boilers that incorrectly report the current max CH water setpoint as the upper bound (like Viessman Vitodens)". Could that be what you are looking for?