Lennox HP21 User Manual

Page 51
CHECK SUPPLY VOLTAGE. IS SUPPLY VOLTAGE
WITHIN RANGE SHOWN ON UNIT RATING PLATE?
HIGH SPEED HEATING
HIGH SPEED COOLING
YES
NO
TABLE 20a
HP21 UNIT CONTROLS DIAGNOSTICS
CORRECT POWER SUPPLY.
MANUALLY RESET HIGH PRESSURE SWITCH S4
IN OUTDOOR UNIT IF TRIPPED.
CHOOSE COOLING OR HEATING MODE
1− TURN INDOOR THERMOSTAT TO OFF POSITION.
2− SET INDOOR THERMOSTAT TO LOWEST TEMPERATURE SETTING.
3− TURN INDOOR THERMOSTAT TO COOL MODE.
4− IF POWER TO OUTDOOR UNIT HAS BEEN OFF, WAIT AT LEAST 10
SECONDS TO ALLOW TSC TO POWER-UP.
5− PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY-
PASS THE 5-MINUTE TIMED-OFF DELAY.
6− ALLOW 1 MINUTE FOR THE UNIT TO START.
1− TURN INDOOR THERMOSTAT TO OFF POSITION.
2− PLACE A JUMPER WIRE ACROSS SPEED CONTROL THERMOSTAT
S55 IN OUTDOOR UNIT.
3− SET INDOOR THERMOSTAT TO HIGHEST TEMPERATURE SETTING.
4− TURN INDOOR THERMOSTAT TO HEAT MODE.
5− IF POWER TO OUTDOOR UNIT HAS BEEN OFF, WAIT AT LEAST 10
SECONDS TO ALLOW TSC TO POWER-UP.
6− PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY-
PASS THE 5-MINUTE TIMED-OFF DELAY.
7− ALLOW 1 MINUTE FOR THE UNIT TO START.
DOES UNIT START AND RUN ON HIGH SPEED?
YES NO
IS UNIT IN COOLING MODE?
REVERSING VALVE SHOULD BE ENERGIZED.
REVERSING VALVE ENERGIZED/
YES NO
CHECK VOLTAGE ACROSS TERMINALS R AND X
AT UNIT LOW VOLTAGE TERMINAL STRIP TB15.
IS VOLTAGE 24+
6VAC?
YES NO
REPEAT TROUBLESHOOTING
PROCEDURE.
CHECK REVERSING VALVE
FOR MALFUNCTIONS.
REPLACE IF NECESSARY.
CHECK INDOOR THERMOSTAT
FOR MALFUNCTIONS.
REPLACE IF NECESSARY.
HIGH SPEED COOLING O.K.
LOW SPEED COOLING
1− TURN INDOOR THERMOSTAT TO OFF POSITION.
2− DISCONNECT THERMOSTAT WIRE FROM TERMINAL Y2 OF HEAT
PUMP LOW VOLTAGE TERMINAL STRIP TB15.
3− SET INDOOR THERMOSTAT TO LOWEST TEMPERATURE SETTING.
4− TURN INDOOR THERMOSTAT TO COOL MODE.
5− IF POWER TO OUTDOOR UNIT HAS BEEN OFF, WAIT AT LEAST 10
SECONDS TO ALLOW TSC TO POWER-UP.
6− PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY-
PASS THE 5-MINUTE TIMED-OFF DELAY.
7− ALLOW 1 MINUTE FOR THE UNIT TO START.
DOES UNIT START AND RUN ON LOW SPEED?
YES NO
YES NO
IS UNIT IN COOLING MODE?
REVERSING VALVE SHOULD BE ENERGIZED.
REVERSING VALVE ENERGIZED/
LOW SPEED COOLING O.K.
TSC OPERATING PROPERLY.
REASSEMBLE UNIT.
DOES UNIT START AND RUN ON HIGH
SPEED IN HEATING MODE?
YESNO
HIGH SPEED HEATING O.K.
LOW SPEED HEATING
1− TURN INDOOR THERMOSTAT TO OFF POSITION.
2− REMOVE THE JUMPER WIRE FROM ACROSS SPEED CON-
TROL THERMOSTAT S55 IN OUTDOOR UNIT.
3− DISCONNECT THE FACTORY WIRING FROM EITHER SIDE
OF SPEED CONTROL THERMOSTAT S55.
4− SET INDOOR THERMOSTAT TO HIGHEST TEMPERATURE
SETTING.
5− TURN INDOOR THERMOSTAT TO HEAT MODE.
6− IF POWER TO OUTDOOR UNIT HAS BEEN OFF, WAIT AT
LEAST 10 SECONDS TO ALLOW TSC TO POWER-UP.
7− PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC
TO BYPASS THE 5-MINUTE TIMED-OFF DELAY.
8− ALLOW 1 MINUTE FOR THE UNIT TO START.
DOES UNIT START AND RUN ON LOW
SPEED IN HEATING MODE?
YESNO
LOW SPEED HEATING O.K.
TSC OPERATING PROPERLY.
REASSEMBLE UNIT.
GO TO B
ON NEXT PAGE
GO TO B
ON NEXT PAGE
YES NO
CHECK VOLTAGE ACROSS TERMINALS O AND X
AT UNIT LOW VOLTAGE TERMINAL STRIP TB15.
IS VOLTAGE 24+
6VAC?
CHECK REVERSING VALVE
FOR MALFUNCTIONS.
REPLACE IF NECESSARY.
CHECK INDOOR THERMO-
STAT FOR MALFUNCTIONS.
REPLACE IF NECESSARY.
REPEAT TROUBLESHOOTING PROCEDURE.
GO TO A
ON NEXT PAGE
GO TO A
ON NEXT PAGE
START
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Lennox HP21 Specifications

General

Brand	Lennox
Model	HP21
Category	Heat Pump
Language	English