Friedrich WallMaster WS07A10D Service Manual page 48

PROBLEM
Noisy operation.
PROBLEM
Water leaks into room.
PROBLEM
Thermostat short
cycles.
PROBLEM
Prolonged off-cycles.
(automatic operation)
PROBLEM
Switches from
cooling to heating.
48
POSSIBLE CAUSE
Poorly installed unit.
Fan blade striking chassis.
Compressor vibrating.
Improperly mounted or loose cabinet
parts.
POSSIBLE CAUSE
Evaporator drain pan overflowing.
Condensation forming on base pan.
Poor installation resulting in rain
entering room.
Condensation on discharge grilles.
POSSIBLE CAUSE
Thermostat differential too narrow.
Plenum gasket not sealing, allowing
discharge air to short cycle thermostat.
Restricted coil or dirty filter.
Tubular insulation missing from top of
thermostat bulb.
Thermostat bulb touching thermostat
bulb support bracket.
POSSIBLE CAUSE
Anticipator (resistor) wire disconnected
at thermostat or system switch.
Anticipator (resister shorted or open).
(Applicable models.)
Partial loss of charge in thermostat
bulb causing a wide differential.
POSSIBLE CAUSE
Thermostat sticking.
Incorrect wiring.
TO CORRECT
Refer to Installation Instructions for proper
installation.
Reposition - adjust motor mount.
Check that compressor grommets have not
deteriorated. Check that compressor mounting parts
are not missing.
Check assembly and parts for looseness, rubbing
and rattling.
TO CORRECT
Clean obstructed drain trough.
Evaporator drain pan broken or cracked. Reseal or
replace.
Check Installation Instructions. Reseal as required.
Dirty evaporator coil - clean. Very high humidity
level.
TO CORRECT
Replace thermostat.
Check gasket. Reposition or replace.
Clean and advise customer of periodic cleaning of
filter.
Replace tubular insulation on bulb.
(Applicable models.)
Adjust bulb bracket.
(Applicable models.)
TO CORRECT
Refer to appropriate wiring diagram.
Disconnect plug from outlet. Remove resistor from
bracket. Insert plug and depress "Cool" and "Fan -
Auto (MoneySaver)" buttons. Place thermostat to
warmest setting. Feel resistor for temperature. If no
heat, replace resistor.
Replace thermostat.
TO CORRECT
Change room thermostat.
Refer to appropriate wiring diagram.