Friedrich CP14-18-24 CP24N30 - Manual (Page 18)

18
Problem Possible Cause Action
Unit cools when heat
is called for
Incorrect wiring Refer to applicable wiring diagram
Defective solenoid coil Check for continuity of coil
Reversing valve fails to shift
Block condenser coil & switch unit to cooling. Allow
pressure to build up in system, then switch to
heating. If valve fails to shift, replace valve.
Inoperative system switch Check for continuity of system switch
Problem Possible Cause Action
Cooling adequate,
but heating
insuffi cient
Heating capillary tube partially restricted
Check for partially starved outer coil. Replace
heating capillary tube
Check valve leaking internally
Switch unit several times from heating to cooling.
Check temperature rise across coil. Refer to
specifi cation sheet for correct temperature rise
Reversing valve failing to shift completely;
bypassing hot gas
De-energize solenoid coil, raise head pressure,
energize solenoid to break loose. If valve fails to
make complete shift, replace valve.
Heat / Cool Room Air Conditioners: Troubleshooting Tips