Troubleshooting | 27LM Series Heat Pump
8 733 905 315 (2013/9)Revised 09-13
UPM Board LED Indications
Indication
Color
Blinks Description
GREEN Solid 18-30 VAC Power is present
RED 1 High pressure lockout
RED 2 Low pressure lockout
RED 3 Freeze sensor lockout
RED 4 Condensate overflow
RED 5 Brownout
RED 6 Evaporator Freeze condition
Comfort Alert Module -Flash Codes
Status LED
Status LED
Description
Status LED Troubleshooting Information Solution
YELLOW "ALERT"
FLASH CODE 3
Short Cycling
Compressor is
running only briefly
1. Thermostat demand signal is intermittent
2. Time delay relay or control board defective
3. If high pressure switch present go to Flash Code 2
information
4. If low pressure switch present go to Flash Code 1
information
YELLOW "ALERT"
FLASH CODE 4
Locked Rotor 1. Run capacitor has failed (may not be bad, verify)
2. Low line voltage (contact utility if voltage at disconnect
is low)
• Check wiring connections
3. Excessive liquid refrigerant in compressor
4. Compressor bearings are seized
• Measure compressor oil level