33
CHART 8 -- UNIT NOT RUNNING OPTIMALLY
Suction and head
equal?
Outdoor coil clean? Clean coil. Problem
persists?
Indoor filter clean? Clean filter. Problem
persists?
Check indoor fan
motor
Connect gauges to
unit. Pressures ok?
Replace indoor fan
motor.
Check compressor
Normal suction,
high head?
High head, high
suction?
Unit is overcharged.
Reclaim charge and
weigh in correct charge
High head, low
suction?
Yes
Yes
Yes
No
No No No
Problem solved
Problem solved
No No
No No
No
Yes
Yes
Yes
Yes
Yes Yes Yes
Check application
limits.
Non condensables
in sys. Pump down
and recharge unit
See note below*
* Restriction in system. Check capillary tube, check for moisture, and check for damage to liquid line between indoor and
outdoor units.
Suction and head
equal?
Outdoor coil clean? Clean coil. Problem
persists?
Indoor filter clean? Clean filter. Problem
persists?
Check indoor fan
motor
Connect gauges to
unit. Pressures ok?
Replace indoor fan
motor.
Check compressor
Normal suction,
high head?
High head, high
suction?
Unit is overcharged.
Reclaim charge and
weigh in correct charge
High head, low
suction?
Yes
Yes
Yes
No
No No No
Problem solved
Problem solved
No No
No No
No
Yes
Yes
Yes
Yes
Yes Yes Yes
Check application
limits.
Non condensables
in sys. Pump down
and recharge unit
See note below*
* Restriction in system. Check capillary tube, check for moisture, and check for damage to liquid line between indoor and
outdoor units.
A08170
38/40MVC, MVQ