Advanced Distributor Products Unit Heater SEP−250-S

Vent and Vent Connector Inspection

Check all vent and vent connector joints for tightness

Are there any blockages in the vents or connectors?

Dispose of any debris or waste found during inspection

Check all wiring for loose connections

Enter the voltage at the unit (unit operating)

Ensure all tools are removed from the inspection area

Is the inspection area clean and free of debris?

Verify that the combustion air inducer starts immediately when the thermostat calls for heat.

Ensure the combustion air pressure switch proves inducer operation before allowing power to the ignition controller.

Confirm that after a prepurge of approximately 30 seconds, the spark ignition is energized and the solenoid valves open in the gas valve.

Verify step opening valve operation for models SEP 230, 250, 300, 345, and 400

Check that the spark ignites the gas and the ignition sensor proves the flame.

Is the combustion process continuing without interruption?

Examine burner flames for proper appearance during the heating season

Examine burners for any deposits or blockage

Turn off both electrical and gas supplies to unit

Disconnect gas supply piping, high tension and sensor leads

Enter the gas line pressure with unit firing at maximum rate

Is the gas line pressure at least 5'' (127mm) w.c for natural gas or 11'' (279mm) w.c for LP/propane gas?

Enter the current regulator pressure

Adjust manifold pressure to the value specified on the unit rating plate

Refer to figures 8, 9, and 10 for gas pressure adjustment screw location