Temperzone UC8 Troubleshooting Guide
Indoor unit serial
comms lost
Indoor unit has no power.
Restore power to the indoor unit.
Use a twisted pair screened cable.
Signals A and B must form a pair.
Connect screen to 0V at the UC8.
Re-route cables away from other
cabling where possible.
The indoor unit should use the
same earth point as the outdoor
unit.
Faulty indoor unit controller.
Replace indoor unit controller.
Indoor unit
controller reports a
fault
Loose temperature sensor wiring in
indoor unit.
Repair temperature sensor wiring
in the indoor unit.
Problem with
variable speed
compressor
inverter
Restore power to the inverter.
Refer to high compression ratio protection (CRH).
Refer to low compression ratio protection (CRL).
High evaporating
temperature
Very high room temperature
combined with high indoor fan speed
(cooling mode).
Temporarily reduce indoor fan
speed.
Excess introduction of fresh (hot
outdoor) air.
Reduce amount of fresh air.
Low condensing
temperature
Very low room temperature combined
with high indoor fan speed (heating
mode).
Temporarily reduce indoor fan
speed.
Excess introduction of fresh (cold
outdoor) air.
Reduce amount of fresh air.
Outdoor coil exposed to strong cold
wind (cooling mode).
Shelter outdoor unit from strong
winds.
Invalid EEV mode
selection
Indoor unit not detected.
Ensure indoor unit powers up at
the same time, or before, the
outdoor unit.
Check wiring between outdoor and
indoor units.
Incorrect DIP switch settings.
Change DIP switch settings, then
reset the controller.