A Midea 3.5kW split system (heatpump 407c), which had been installed almost 1-year ago, was playing up on Friday. The warning lights implied “over current protection” and after 4x auto-resets, it tripped out. The customer said that he had been overcoming this by switching the system off at the isolator, and then switching back on “and that seemed to clear it”. Well, shutting off and switching back on does reboot the system’s protection controls but it does not deal with the underlying cause. And the problem has been repeating. Looking around the system, the condenser was clear of debris and no sign at all of frosting up (you could see right through the fins). Outside temp was about 2degC. The controller was set on 27 degC (women!) and the room was warm at about 25 degC (so the split was trying its heart out to satisfy them. The equipment distributor said that the warning lights indicated overcurrent and this could come about through maybe loose electrical connections, or maybe there was too much refrigerant gas in the system. The only other idea was maybe the high discharge pressures were stemming from the high desired temperature on the controller. I have an engineer calling in on Monday to check the terminals to make sure nothing is loose. He is certain that the fridge charge is correct, topping up only a small amount to cover the measured run, per specified rate/meter. That would just leave the high room temperature. Any other ideas of likely causes or things to check out?