Advanced Distributor Products Unit Heater SEP−250-A

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?

Enter the gas line pressure with unit firing at maximum rate

Is the gas line pressure above the minimum required level?

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

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

Verify thermostat calls for heat

Check if combustion air inducer starts immediately

Combustion Air Pressure Switch Verification

Ensure combustion air pressure switch proves inducer operation

Confirm no adjustment is necessary for the factory-set switch

Ignition and Gas Valve Operation

Record prepurge duration (should be approximately 30 seconds)

Verify spark ignition is energized

Inspect the combustion air inducer for any visible damage or wear

Use a small brush to clean the inducer wheel

Is the combustion air inducer clean and free of debris?