Classic HVPA & HVPSA M&S 8.09-1
15700 - 15
HVAC Equipment
Heating Mechanical Checks Flow Chart
Unit Running?
YES
NO
Pressure Problems?
Go to Electrical
Checks Flow Chart
High Head
Pressure
Low Head
Pressure
Low Suction
Pressure
Dirty Filters
Low on Charge
Dirty Outdoor Coil
Dirty Indoor Coil
Low Indoor
Temperature
Inadequate Air Flow
Over Outdoor Coil
Inoperative Indoor
Blower
Closed Indoor Check
Valve
Inoperative OD Fan
Overcharge
Inoperative
Compressor Valves
Low on Charge
Inadequate Indoor Air
Flow
Restricted Outdoor
Metering Device
Restricted Outdoor
Metering Device
Non-condensibles
Restricted Filter Drier
Restriction in System
Wrong Indoor Blower
Rotation
Reversing Valve Failure Closed Indoor Check
Valve
Inadequate Ducts
Recirculation of Out
-
door Air
Restricted Filter Drier
Defrost Mechanical Checks Flow Chart
Defrost System
No Defrost
Incomplete Defrost
Excessive Defrost
Reversing Valve Stuck
Poor Sensor Location
Wrong Defrost Control
Timer Setting
No Defrost Timer
Control Power
Wrong Defrost Control Timer
Setting
Poor Sensor Location
Failed Defrost Control
Failed Defrost Relay (doesn’t
stop O.D. Fan)
Low System Charge
Failed Defrost Relay
Thermostat Satisfies During
Defrost
Wind Affecting in Defrost
Loose Default Sensor
