Digital Control Diagnostics and Test Mode
Diagnostics
The Friedrich Smart Center continuously monitors the PTAC unit operation and will store service codes if certain conditions are witnessed. In some cases the unit may take action and shut the unit off until conditions are corrected.
To access the error code menu press the ‘Heat’ and ‘High Fan’ buttons simultaneously for three seconds. If error codes are present they will be displayed. If multiple codes exist you can toggle between messages using the temp 
button. To clear all codes press the temp 
button for three seconds while in the error code mode. To exit without changing codes press the ‘Low Fan’ button.
The chart below lists the possible error codes and their description:
Test Mode
For service and diagnostic use only, the
Error | Code Translation | Action Taken by Unit |
| Possible Cause | |
Code |
| ||||
|
|
|
| ||
01 | NOT USED | NONE |
|
| |
| An extreme low voltage condition | Shut down unit. Display Error code and flash. | • | Inadequate power supply | |
02 | exists <198V for 230V units and | Once voltage rises to normal level system power | • | Defective breaker | |
| <239V for 265V units. | is restored. | • | Blown fuse | |
|
|
|
|
| |
03 | Return air thermistor sensor open | Set return air sensor = 75°F. Alternate flash set | • | Defective sensor | |
or short circuit | point and error code. Leave unit running. | ||||
|
|
| |||
|
|
|
|
| |
04 | Indoor coil thermistor sensor open | Set ID coil temp = 40°F. Alternate flash set point | • | Defective sensor | |
Or short circuit | and error code. Leave unit running. | ||||
|
|
| |||
|
|
|
|
| |
| Outdoor coil thermistor sensor | Set OD coil temp = 20°F. Alternate flash set point | • | Defective sensor | |
05 | and error code. Automatically change over to | ||||
open Or short circuit | |||||
| Electric heat Mode only. Leave unit running. |
|
| ||
|
|
|
| ||
|
|
|
|
| |
|
|
| • | Dirty coil | |
| If O.D. coil Temperature > 175 Deg | Alternate flash set point and error code. Shut unit | • | Fan motor failure | |
06 | F for 2 consecutive minutes. (Heat | down for 5 minutes, then try again 2 times, if fails | • | Restricted air fl ow | |
| Pump models only) | the 3rd time, then shut down unit. | • | ||
|
|
| |||
|
|
|
| refrigeration system | |
|
|
|
|
| |
|
| Alternate flash set point and error code. Continue | • | Dirty fi lters | |
|
| • | Dirty coil | ||
|
| fan operation while the compressor is locked out | |||
|
| • | Fan motor failure | ||
07 | I.D coil temperature <30 Deg F for | until the indoor coil thermistor reaches 45° F, and | |||
2 consecutive minutes. | then energize the compressor. However, com- | • | Restricted airfl ow | ||
| |||||
|
| pressor must still wait a lockout time of 180 to 240 | • | Improper refrigerant charge | |
|
| seconds. | |||
|
| • | Restriction in refrigerant circuit | ||
|
|
| |||
|
|
|
|
| |
08 | If unit cycles (Heat or Cool | Alternate flash set point and error code. Keep unit | • | Unit oversized | |
demand)> 9 times per hour | running. | • | Low load conditions | ||
| |||||
|
|
|
|
| |
09 | If unit cycles (Heat or Cool | Alternate flash set point and error code. Keep unit | • | Unit undersized | |
demand)< 3 times per hour | running. | • | High load conditions | ||
| |||||
|
|
|
|
| |
10 | Room Freeze Protection triggered | Alternate flash set point and error code. Keep unit | • | Room temperature fell below 40°F | |
running. | |||||
|
|
|
| ||
|
|
|
|
|
24
