Sanyo aircon fault.

[Tom1979]

I'm working on a SPW-CR483EHL8 and the controller is showing a P04 fault which according to my fault codes is a HP fault. However the unit does not start. It doesn't run at all and faults about 5 minutes after turning it on. Ive got a working system on site and have used this to check all electrical components work. Which they do.

Anyone else had anything like this. Unit has gas charged in it. HP Switch also appears not faulty and is also not open when faulting out. I'm rather confused!!!!!!!

[RusBuka]

High-pressure switch operation
(Both cooling and heating)
• Electronic refrigerant control valve
defect
(indoor unit)
(Cooling)
• Outdoor unit, heat exchanger dirty,
clogged
• Outdoor unit air short
• Outdoor fan stopped
• Refrigerant over-charged
(Heating)
• Outdoor unit air short
• Indoor unit, heat exchanger dirty,
clogged
• Large pipe side service valve
closed
• Indoor fan stop
• Air filter clog

[joe-ice]

I wouldnt take it for granted that the switch open circuits on high pressure could be the other way around.Can you meter the hp switch on the good unit to see if its normally open.