EXCESSIVE COMBUSTION VENT OR FLUE BLOCKAGE | If pressure against induced draft blower outlet becomes excessive, the pressure switch will open and shut off the gas valve until acceptable combustion pressure is again available |
LOSS OF FLAM | If loss of flame occurs during a heating cycle, or flame is not present at the sensor, the flame control module will close the gas valve. The flame control module will then recycle the ignition sequence, then if ignition is not achieved, it will shut off the gas valve and lock out the system. |
POWER FAILURE | If there is a power failure during a heating cycle, the system will restart the ignition sequence automatically when power is restored, if the thermostat still calls for heat |
GAS SUPPLY FAILURE | If loss of flame occurs during a heating cycle, the system integrated control module will recycle the ignition sequence, than if ignition is not achieved, the integrated control module will shut off the gas valve and lock out the system. |
INDUCED DRAFT BLOWER FAILURE | If pressure is not sensed by the pressure switch, the contacts will remain open and not allow the gas valve to open, therefore the unit will not start. If failure occurs during a running cycle, the pressure switch contacts will open and the gas valve will close to shut the unit down. |
CONDENSATE DRAIN BLOCKAGE | If the condensate drain is blocked, either by debris, im- proper draining, or by freezing condensate, the pressure switch will sense the accumulation of condensate in the furnace drain pan. The pressure switch contacts will open and remain open, not allowing unit operation. The unit will not operate until the condensate drain has been cleared, and the condensate flows freely |
RESET AFTER LOCKOUT | When the integrated control module has shut the system down and gone into lockout, the system must be manually reset before the unit will restart. To reset, turn the system power off, then on, then off and then on again within 30 seconds. This may be done at the unit’s power source or at the thermostat. The system will not reset unless the procedure off-on-off-on is completed within 30 seconds. |
RESET AFTER BURNER BOX LIMIT SHUTDOWN | If the furnace shuts down, one thing that can be checked is the burner box temperature limit switch. It is located on the bottom of the burner box. The vent and combustion air inlet terminations should be checked for blockage. If blockage exists, clear the problem and then the reset button may be depressed. |