Operating instructions

14
PROBLEM POSSIBLE CAUSE CHECKS AND CORRECTIONS
Unit Short Wiring and Controls Loose wiring connections, or control contactor defective.
Cycles Compressor Overload Defective compressor overload, check and replace if necessary.
(Continued) If the compressor runs too hot, it may be due to a insufficient
refrigerant charge.
Water Lack of sufficient pressure, temperature, and/or quantity of water.
Unit Undersized Recalculate heat gains or losses for space to be conditioned. If
excessive, rectify by adding insulation, shading, etc.
Loss of Conditioned Air Check for leaks in ductwork or introduction of ambient air through
by Leaks doors and windows.
Thermostat Improperly located thermostat (e.g. near kitchen), inaccurately
sensing the comfort level in the living area. Check anticipator
setting.
Insufficient Airflow Lack of adequate airflow or improper distribution of air. Check the
cooling or motor speed or duct sizing. Check the filter, it should be inspected
heating. every month and changed if dirty. Remo ve or add resistance
accordingly.
Refrigerant Charge Low on refrigerant charge causing inefficient operation. Adjust only
after checking CFM and GPM.
Compressor Check for defective compressor. If discharge pressure is too low
and suction pressure is too high, compressor is not pumping
properly. Replace compressor.
Reversing Valve Defective reversing valve creating bypass of refrigerant from
discharge to suction side of compressor. When it is necessary to
replace the reversing valve, wrap it with a wet cloth and direct heat
away. Excessive heat can damage the valve.
Desuperheater The desuperheater circuit (in-line fuse) should be disconnected
during cold weather to allow full heating load to the house.
Dirty Filter Check filter. Clean or replace if found dirty.
Thermostat Improperly Set Check if thermostat is set at correct temperature.
Unit will not Defective Thermostat Check thermostat operation. Replace if found defective.
operate on Incorrect Wiring Check for broken, loose, or incorrect wires.
"heating" Blower Motor Defective Check blower motor in one of the other switch positions. If it does
not operate, check for open overload. If overload is open and
motor is not overheated, replace it.
Reversing Valve Does Not
Shift
Defective solenoid valve will not energize. Replace solenoid coil.
Unit does not Reversing Valve Does Not The solenoid valve is de-energized due to miswiring at the unit or
cool Shift, the Valve is Stuck thermostat--correct wiring. Replace if valve is tight or frozen and
(Heats only) will not move. Switch from heating to cooling a few times to loosen
valve.
Compressor Make sure the compressor is not in direct contact with the base or
sides of the cabinet.
Cold surroundings can cause liquid slugging. Increase ambient
temperature.
Blower and Blower Motor Blower wheel hitting the casing. Adjust for clearance and
alignment. Bent blower, check and replace if damaged. Loose
blower wheel on shaft, check and tighten. Defective bearings,
check and replace.
Noisy Contactors A clattering or humming noise in the contactor could be due to
Operation control voltage less than 18 volts. Check for low supply voltage,
low transformer output, or extra long runs of thermostat wires.
If the contacts are pitted or corroded , or coil is defective, repair
or replace.