Panasonic S-45PU1E5 Technical Data & Service Manual page 297

E20 No indoor units connected
1. Error Detection Method
It is judged an error if an indoor unit cannot be recognized at the start of auto address setting or when the outdoor unit is turned
on.
The address(es) of indoor unit(s) are not assigned correctly.
•
The indoor unit is not turned on.
•
2. Error Diagnosis
1 Indoor Unit
1-1 Are the address(es) of indoor unit(s) assigned correctly?
1-2 Are the indoor units turned on?
The indoor/outdoor control line may be disconnected somewhere between the indoor unit(s)
1-3
and the outdoor unit. Check and make sure the indoor/outdoor control line is connected.
5-25
Yes 1-2
No Set its address
Yes 1-3
No Power on
5