Pioneer WYD009AL3JAR-L Service Manual page 15

Symptom : In HEAT Mode, indoor unit is blowing cold air instead of heating.
Reason : Missing wire connection, defective reversing valve actuator.
Solution : Otherwise, assure that the YELLOW wire is attached to terminal #3 on the outdoor unit. Also
check that the same yellow wire is either connected to the #3 terminal on the indoor unit (009, 012, 018
models) or the white plug at the end of the cable at the indoor side is plugged with the matching white plug on
the indoor unit properly (for 024 models only). While in Heat Mode: Check for voltage between #3 and N
terminals on 115V models and assure it reads 115V or check between #3 and L2 terminals on 230V models and
assure it reads 230V (at the outdoor unit's terminal block).
Symptom : Both indoor and outdoor units run but there is no heating or cooling.
Reason : Valves were not fully opened, like set is kinked, refrigerant was lost.
Solution : Assure that the system was properly vacuumed before releasing the refrigerant. Assure both
valves on the outdoor unit were fully opened. Assure there are no refrigerant leak at any of the 4 flare
connections attached during installation. Check for pressure reading in cool mode to be approx 120 PSI and both
copper pipes to be very cold and sweating. Check for pressure reading in heat mode to be approx 400 PSI and
both copper pipes to be very hot.
Symptom : In heat mode outdoor unit runs but indoor unit fan does not start blowing.
Reason : System is in warm Start Mode. If extended this can mean refrigerant loss.
Solution : When the compressor first starts in heat mode, indoor fan is delayed until the indoor coil
surface gets hot enough to produce warm air discharge. The fan starts blowing once the indoor coil is warmed.
This takes maximum 1 minute. If this is extended further, than check for operating pressures and assure the
system has no refrigerant leaks.
Symptom : System does not start cooling or heating as soon as it is started.
Reason : System is in protection time delay mode.
Solution : When the system is started, the compressor does not start immediately. There is a 3 minute
time delay for protection.
Symptom : Indoor unit seems totally dead. No lights.
Reason : Power connection from the outdoor unit is not made properly or fuse was blown.
Solution : Check for the voltage between L and N terminals on the indoor units terminal block (for 115V
systems) to read 115 VAC. Check for the voltage between L1 and L2 terminals on the indoor units terminal block
(for 230V systems) to read 230 VAC. Check the other end of the same wires on the outdoor unit for the same
voltage. Assure the breaker is not tripped. If the voltage is present on the indoor unit, fuse may be blown on the
controller card of the indoor unit. Replace with a 5A fuse. Or replace the control card.
Symptom : Indoor unit fan runs continuously in cooling mode.
Reason : This is a normal and required condition programmed by the internal software.
Solution : Indoor fan must run continually in cooling mode to be able to sample the air temperature and
call for the compressor to cycle on when needed. This is normal. Indoor fan motor operates on only a few
pennies a day, so it will not waste any significant amount of energy, plus it will provide a positive air circulation
for better comfort.
Symptom : Indoor unit fan comes on and off briefly in heat mode.
Reason : This is a normal and required condition programmed by the internal software.
Solution : Indoor fan must runs once in a while to sample the air temperature and call for the compressor
to cycle on when needed. This is normal. Unlike the cooling mode, indoor fan does not run continually in cooling
mode to prevent cols air draft. The temperature swings in the space between the on and off modes will be
slightly higher than the cooling mode.