Split A/C unit not working in heat pump mode

[Matt34]

Hi

Would anyone like to give any thoughts on a fault I have with a KWS-66GW/X1c split, capillary tube model R410a.

In cooling mode it works fine. 6.5bar suction and 9bar discharge. Throwing off heat at condenser. (18c) at 3deg ambient(outside). Evaporator 3C at suction line(inside ambient 20c).

When I switch to heating mode it instantly faults to E5 (overpressure) with compressor not even running.

Over pressure sensor located in evaporator. Measured voltage across sensor and have 1.6 volts. Sensor is brazed into evaporator coil. (no adjustment)

I was thinking it might be the PCB/sensor fail?

Thanks, Matt

[Matt34]

Fixed problem. Pressure sensor is actually clipped into brazed sleeve. Pressure sensor is actually a temp sensor. Changed sensor and everything fine. Thanks for everyone who looked at the post.