In the next few months I’m having an ASHP installed (LG therma V) and I’d like to make sure I have everything in place to be able to monitor it appropriately via OEM. The most pressing question is which heat meter to have installed - I’ve read that the Kamstrup 402 & 403 and Sontex 531 are all compatible with the heat pump monitor. It seems the 402 is discontinued and the 403 is somewhat expensive so currently looking at the Sontex option.
What I’m wondering is whether anyone has any experience using a Sontex 739, 749 or 789 which appear to be cheaper? If not, is it likely to be much of a task to update the M-BUS code to include these meters (i.e. if I bought one and had to do it myself)?
Or, is there a better way? The heater meter would be installed purely for my own monitoring purposes so if there is a more economic solution I would be interested to hear about it.