Vaillant Arotherm Owners Thread

[Timbones (Tim)]

John Cantor was observing this same phenomenon on his Mitsubishi…

Anyone monitoring a new R32 Ecodan?

Hello David, I have got nowhere with Mitsubishi. They are not interested in my pocking into finer details. Given that I probably cannot sell this 6kW easily, I think I will need to make a control like yours and make the best of it. My issue is different to yours. Mine is not oversized, but COP seems to ‘crash’ sometimes. I am getting excellent COPs at times and will probably spend my time working out how to control it better and minimise the ‘crashes’. See the graph showing a big dip in outpu…

It’s something to do with the “compressor discharge temperature” and where the evaporation happens.

Anyone monitoring a new R32 Ecodan?

I am not the person to ask about getting that data out. Others might know. I fitted an ds18b20 sesnor to the compressor discharge pipe (red line). It’s tricky to fit well onto such a small pipe. This was very useful for seeing what was happening. As this shows, the discharge should be superheated (as times when COP is good). Where the discharge temperature drops to a similar value as the flow temperature, the COP is very poor [image]