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Marvair Classic AVPA/HVPA/HVPSA Heat Pump I&O Manual
11/2017 Rev. 7
would be very grateful if you would bring it to the attention of our service department for incorporation
in future revisions.
As always, please exercise caution and good judgement when servicing your Heat Pump. Use only safe
and proven service techniques. Use refrigeration goggles when servicing the refrigeration circuit.
The refrigerant circuit has hot surfaces, and the electrical voltages inside of the unit may be hazardous or
lethal. SERVICE MAY BE PERFORMED ONLY BY QUALIFIED AND EXPERIENCED PERSONS.
WARNING
The refrigerant circuit has hot surfaces, and the electrical voltages inside of the unit
may be hazardous or lethal. SERVICE MAY BE PERFORMED ONLY BY QUALIFIED
AND EXPERIENCED PERSONS.
4.2 Failure Symptoms Guide
PROBLEM/SYMPTOM
LIKELY CAUSE(S)
CORRECTION
A. Unit does not run.
NOTE: An internal anti-short-cycle
timer will prevent the unit
from starting for .2 to 8
minutes following start-up.
1. Power supply problem.
2. Tripped internal disconnect.
3. Shut off by external thermostat or
thermostat is defective.
4. Unit off on high pressure or loss of
charge.
5. Internal component or connection
failure.
1. Check power supply for adequate phase and
voltage. Check wiring to unit and external
breakers or fuses.
2. Check circuit protection devices for
continuity.
3. Check operation of wall-mounted thermostat.
4. Reset lockout. See section 1.4.
5. Check for loose wiring. Check components
for failure.
B. Unit runs for long periods or
continuously; cooling is insufficient.
1. Unit undersized for job.
2. Low refrigerant.
3. Component failure.
4. Dirty filter or reduced airflow.
1. Add additional units for greater capacity.
2. Check for proper charge and possible refrig-
erant leak.
3. Check internal components, especially com-
pressor for proper operation.
4. Check air filter(s). Check blower operation.
Remove airflow restriction.
