Hi all,   We had our ASHP replaced with a 16kw Samsung. It's worked fine for a few months.   Now I get this error message, often (if not always) when nothing is calling for heat. I understand from doing a bit of research that it is to do with the flow of water and maybe the flow switch/sensor - this is a new one that comes with the gen6 I believe.   When somethign IS calling for heat, it can run all day without throwing up the is error.   I've seen videos