daikin error code UH

[sanz]

Dear all,
Pls give me a solution for this,
I found UH error code on one fcu and A5 error code on another fcu. Both are connected to the same CU.(4mks80E)
I have checked these things.
Indoor outdoor compatiblity.
Indoor outoor wiring and copper piping.
Pls help me to figure out this issue.
Is it pcb faullt fault.

[Po65]

I think the A5 is a thermistor fault and uh is I wiring/ pcb with outdoor

[install monkey]

A5 Operation halt due to the freeze protection function or high pressure control
U4 Signal transmission error (between indoor and outdoor units)
UH Improperconnection of
transmission
wiring between
outdoor and
outdoor unit
outside control
adaptor

[install monkey]

lev's on outdoor are prone to sticking

[install monkey]

https://drive.google.com/file/d/0Bz6...ew?usp=sharing
service manual

[frank]

From memory, Brian_UK had one of these faults a few years back - I think it's something to do with VAM'S.

There again, I am probably wrong

[install monkey]

test cables are correct 1.2.3 corresponds with indoor 123 and check pipework isnt crossed ie unit A is piped to ports A and wired at port A terminals

[aircon50]

If it's a system I've not seen before I will always carry out a wiring error check. Use SW3 on exterior service monitor PCB. This will confirm as Install Monkey as above.
I've had UH a couple of times and it was a EEV coil each time. The EEV with a faulty coil does not shut and allows refrigerant to pass through an interior unit that is not in operation.