68-0173—3 42
Fig. 41. Troubleshooting procedures (Continued).M18743
TEMPERATURE CHANGES
OCCUR AT THE WRONG TIMES.
PC8900 PROGRAMMED INCORRECTLY. • CHECK THE PROGRAM TIMES FOR THE PERIOD IN QUESTION.
BE SURE THAT AM AND PM INDICATIONS ARE CORRECT.
MAKE SURE THE CURRENT DAY AND TIME ARE CORRECT.
REPROGRAM IF NECESSARY.
PRESENT SETTING APPEARS
INACCURATE.
ADAPTIVE INTELLIGENT RECOVERY™
IS SELECTED.
• REMEMBER THAT WITH
ADAPTIVE INTELLIGENT RECOVERY™
THE HEATING OR COOLING SYSTEM COMES ON BEFORE
THE WAKE AND RETURN START TIMES SO THE HOUSE WILL
BE AT THE DESIRED TEMPERATURE WHEN THE PERIOD
STARTS. SYSTEM CAN BE CONFIGURED FOR CONVENTIONAL
RECOVERY. REFER TO INSTALLATION SECTION.
ADAPTIVE INTELLIGENT RECOVERY™
IS SELECTED.
AND KEYS BEING USED
TO ADJUST TEMPERATURE.
• REPROGRAM PC8900 TO MAKE PERMANENT CHANGE IN
PROGRAM. REFER TO PROGRAMMING INSTRUCTIONS.
HEAT AND COOL SETPOINTS
NEED TO BE ADJUSTED
REGULARLY.
TIME AND DAY HAVE BEEN LOST DUE
TO POWER OUTAGE.
• REPROGRAM TIME AND DAY. REFER TO PROGRAMMING
INSTRUCTIONS.
PC8900 DISPLAY FLASHES
DURING OPERATION.
PARTIAL PC8900 DISPLAY. INOPERATIVE PC8900. • REPLACE PC8900.
• REMEMBER THAT WITH
ADAPTIVE INTELLIGENT RECOVERY™
THE HEATING OR COOLING SYSTEM COMES ON BEFORE
THE WAKE AND RETURN START TIMES SO THE HOUSE WILL
BE AT THE DESIRED TEMPERATURE WHEN THE PERIOD
STARTS. SYSTEM CAN BE CONFIGURED FOR CONVENTIONAL
RECOVERY. REFER TO INSTALLATION SECTION.
COOLING WILL NOT COME ON. NO POWER TO W8900. • CHECK SYSTEM FUSE OR CIRCUIT BREAKER AND
REPLACE OR RESET IF NECESSARY.
• CHECK THAT COOL SYSTEM POWER IS ON.
• CHECK FOR LOOSE CONNECTIONS AT PC8900, W8900,
C7189, OR EQUIPMENT.
PC8900 SYSTEM SETTING IS INCORRECT. • CHECK THAT PC8900 IS SET TO COOL OR AUTO.
5-MINUTE COMPRESSOR PROTECTION
ACTIVATED.
• THE PC8900 HAS A 5-MINUTE BUILT-IN TIME DELAY (IF
ACTIVATED). ALLOW UP TO FIVE MINUTES AFTER CHANGING
THE SETTING BEFORE THE COMPRESSOR STARTS.
PC8900 INOPERATIVE. • CONDUCT SELF-TEST. SEE CHECKOUT.
• REFER TO MANUFACTURER SPECIFICATIONS TO
TROUBLESHOOT EQUIPMENT.
INCORRECT WIRING. • SEE WIRING DIAGRAM.
COOLING EQUIPMENT IS INOPERATIVE. • REFER TO MANUFACTURER SPECIFICATIONS TO
TROUBLESHOOT EQUIPMENT.
COOLING SETPOINT IS TOO HIGH. • ADJUST SETPOINT USING AND KEYS.
ROOM TEMPERATURE AT REMOTE
SENSOR LOCATION IS TOO LOW.
• RELOCATE REMOTE SENSOR WHERE IT IS NOT AFFECTED
BY HOT AREAS, COLD AREAS, OR DEAD-AIR AREAS.
PC8900 CONFIGURED FOR ONLY ONE
STAGE OF COOLING.
• RECONFIGURE PC8900 TO ACCOMMODATE ALL STAGES OF
COOLING.
SYSTEM FAN IS RUNNING
INDEPENDENT OF HEATING
OR COOLING EQUIPMENT.
PC8900 IS CONFIGURED FOR ELECTRIC
HEAT FAN OPERATION.
• RECONFIGURE PC8900 FOR NO ELECTRIC HEAT FAN.
PC8900 IS CONFIGURED FOR OVERRUN
IN COOLING.
• RECONFIGURE PC8900 FOR NO FAN OVERRUN IN COOLING.
PC8900 FAN SETTING IS SET AT
FAN CIRC.
• CIRCULATING FAN FEATURE ALLOWS FAN TO OPERATE
INDEPENDENT OF HEATING OR COOLING EQUIPMENT.
REFER TO OPERATION SECTION.
SYMPTOM POSSIBLE CAUSE ACTION