E-3

Motor error

No cavity motor rotation detected for greater than 30 seconds.

1. Connection between Variable Frequency Drive (VFD) and control board
2. Connection between fan motor and VFD
3. Fan motor
4. VFD
5. Control board

E-10

Sensor short

Short circuit detected on sensor wires.

1. Sensor connection
2. Sensor
3. Control board

E-11

Sensor open

Cavity air sensor reading > 650°F (343°C).

1. Sensor connection
2. Sensor
3. Control board

E-30

Unit under temperature

Cavity temperature remains 25°F (14°C) below target for more than 90 minutes.

Troubleshoot heating element

E-31

Electronics over temperature

Control board temperature exceeds 158°F (70°C) and/or interface board temperature exceeds 184°F (84°C).

1. Cooling fan filters blocked or dirty
2. Cooling fan not operating
3. Installation clearance requirements not met

E-87

Gas lockout

Loss of flame three times within 5 minutes.

Lack of fuel pressure.

E-88

Ignition module/valve failure

Two, 4-second tries for light at the ignition module with a 30-second delay between.

1. Valve status is not open after call for heat.

E-90

Gas combustion blower speed failure

Blower RPM is outside +/- 10% of expected RPMs at start of call for heat, or post-ramping when the end speed is reached.

1. Power supply cable is not connected to blower motor.
2. Speed control cable is not connected to blower motor.
3. Blower motor is blocked, rotation is impeded, or motor is faulty.
4. Faulty PWM daughter board.

E-94

Interface Board - Control Board communication error

No signal transfer for more than 5 seconds between the interface board and the control board.

1. Connection of modbus cable
2. Modbus cable
3. Control board
4. Interface board

E-108

Bi-metal thermostat open

Open circuit detected across bi-metal switch.

1. Cooling fan filters blocked or dirty
2. Cooling fan not operating
3. Connection between bi-metal switch and control board
4. Installation clearance requirements not met
5. Bi-metal switch

E-109

High limit error

Note: Contact an authorized
Alto-Shaam service partner.

Open circuit detected across high limit switch.

1. Jet plate(s) improperly installed
2. Cavity fan not operating
3. Optional grease filters blocked with debris
4. Heat relay(s) stuck closed
5. Connection between high limit switch and control board
6. High limit switch