Subject to change without notice.
8
PHH50–150G3
REV — 6/15/20
TROUBLESHOOTING GUIDE
WARNING:
BE AWARE OF HIGH POWER SITUATIONS WHILE TROUBLESHOOTING. THERE ARE
ALSO MOVING BELTS, BLOWERS, AND MOTORS WHILE POWER IS CONNECTED
TO THE UNIT. WHEN REACHING INTO ANY OF THE UNIT SECTIONS TO MAKE
ADJUSTMENTS TO THE UNIT. PLEASE DISCONNECT POWER FROM THE UNIT.
Problem
Cause
Description
Control is erratic
Loose wiring connections
Check wiring for loose connections, screw terminals, or lugs
Broken V-Belt
Replace V-Belt.
Circuit Breaker
Turn ON Circuit Breaker (CB5).
Check for tripped Circuit Breaker (CB5).
Replace if defective.
Check operational current (amperage).
System ON/OFF Switch
Check to see System ON/OFF Switch is turned ON.
No Heating
Thermostat Setting
Check thermostat setting and increase if required.
Air Switch
Check adjustment on air switch.
Test and replace defective air switch.
Circuit Breakers
Turn on Heating Circuit Breakers (CB1 – CB4).
Check for tripped Heat Circuit Breakers (CB1 – CB4).
Replace if defective.
Check operational current (amperage).
Power Light
Light OFF
No Power to the unit. Check Voltage at the Main Power Supply.
Check Control Panel Fuses F1, F2, F3.
Check LP1 to see if it’s burned out.
System short cycles
Reduced airflow
Increase the airflow by disconnecting power and closing the
motor sheave a turn or two. Verify motor amps is under the
nameplate rating.
Check for kinks or excessive turns in the ducting.
Check for dirty air filters and clean as necessary
Check for broken or loose v-belts.
Discharge Air Thermostat
Check to see if the Discharge Air Thermostat is set between
150°F and 160 °F.
