Lennox Error Code Yellow demand indication

What It Means

• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: G - Blower on
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: GLO - Global input
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: OCP - Occupied
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: W1 - First-Stage Heating
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: W2 - Second-Stage Heating
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: Y1 - First-Stage Cooling
• M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER: Yellow thermostat input indicates demand: Y2 - Second-Stage Cooling