Pump speed

[wintersteiger]

Does anybody happen to know whether there is an OpenTherm data ID for the CH pump speed? It doesn't seem to be in the version 2.2 specification, but I would imagine that there is one in later revisions. I would like to see that just so I can tell when and for how long the pump is running.

[hvxl]

There is no Opentherm data ID defined for real-time information about the pump in newer versions of the Opentherm spec either. Probably that information is not considered relevant for a thermostat to be able to control the boiler.

The only data IDs that can give you some idea of when and how long the pump has been running are: ID117 (CH pump starts) and ID121 (CH pump operation hours).

[wintersteiger]

That's a good point - it probably is indeed irrelevant for a thermostat.