I have a 22kw HGL IDM heat pump running without any problem for 4 years. Recently it came up with a huge pressure fault. I had the installer service the unit and they found one filter clogged on the tank heating circuit. It has not resolved the problem.
Any ideas what the problem could be?
Has anyone got schematics of an IDM heat pump so I can see exactly where this pressure transducer is and what circuit it relates to.