LUBRICATION
The fan shaft bearings, the 1 to 2 HP supply fan motors the condenser fan motors and compressors are permanently lu- bricated.
UNDERCHARGE
An undercharged heat pump on the heating cycle will cause low discharge pressure resulting in low suction pressure and frost accumulation on the outdoor coil.
FUNCTIONAL PARTS
Refer to the unit Parts Catalog for a list of functional parts. Parts are available from your distributor.
SERVICE
THE FOLLOWING INFORMATION IS FOR USE BY QUALI- FIED SERVICE AGENCY ONLY: OTHERS SHOULD NOT ATTEMPT TO SERVICE THIS EQUIPMENT.
Common Causes of Unsatisfactory Operation of Heat Pump on the Heating Cycle.
INADEQUATE AIR VOLUME THROUGH INDOOR COIL
When a heat pump is in the heating cycle, the indoor coil is functioning as a condenser. The return air filter must always be clean, and sufficient air volume must pass through the indoor coil to prevent excessive discharge pressure, and high pressure cut out.
OUTSIDE AIR INTO RETURN DUCT
Do not introduce cold outside air into the return duct of a heat pump installation. Do not allow air entering the indoor coil to drop below 65° F. Air below this temperature will cause low discharge pressure, thus low suction pressure, and exces- sive defrost cycling resulting in low heating output. It may also cause false defrosting.
POOR “TERMINATING” SENSOR CONTACT
The unit’s defrost terminating sensor must make good ther- mal contact with the outdoor coil tubing. Poor contact may not terminate the unit’s defrost cycle quickly enough to pre- vent the unit from cutting out on high discharge pressure.
MALFUNCTIONING REVERSING VALVE - THIS MAY BE DUE TO:
1.Solenoid not energized - In order to determine if the solenoid is energized, touch the nut that holds the solenoid cover in place with a screwdriver. If the nut magnetically holds the screwdriver, the solenoid is energized and the unit is in the cooling cycle.
2.No voltage at unit’s solenoid - Check unit voltage. If no voltage, check wiring circuit.
3.Valve will not shift:
a.Undercharged - check for leaks;
b.Valve Body Damaged - Replace valve;
c.Unit Properly Charged - If it is on the heating cycle, raise the discharge pressure by restricting airflow through the indoor coil. If the valve does not shift, tap it lightly on both ends with a screwdriver handle. DO NOT TAP THE VALVE BODY. If the unit is on the cooling cycle, raise the discharge pressure by restricting airflow through the outdoor coil. If the valve does not shift after the above attempts, cut the unit off and wait until the discharge and suction pressure equalize, and repeat above steps. If the valve does not shift, replace it.
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