Gas Fired High Efficiency Unit Heater - General Maintenance

Should maintenance be required, perform the following inspection and service routine:

• Inspect the area near the unit to be sure that there is no combustible material located within the minimum clearance requirements listed in this manual.

• Turn off the manual gas valve and electrical power to the unit heater.

• Remove service access panel.

• To clean or replace the burner, remove retainer from around manifold orifice, disconnect flame sensor and igniter from control board, remove burner assembly mounting screws. See Figure 31.

• With the burner removed, wire brush the inside surfaces of the heat exchanger.

• Remove any dirt, dust, or other foreign matter from the burners using a wire brush and/or compressed air. Ensure that all parts are unobstructed.

• Reassemble the unit heater by replacing all parts in reverse order

• Complete the appropriate unit startup procedure as given in the “Operation” section of this manual. (See lighting instruction on the unit nameplate).

• Check the burner adjustment.

• Check all gas control valves and pipe connections for leaks.

• Check the operation of the automatic gas valve by lowering the setting of the thermostat, stopping the operation of the gas unit heater. The gas valve should close tightly, completely extinguishing the flame on the burner.

• Inspect and service motor/fan assembly. To maintain efficient air flow, inspect and clean the fan blades and guard to prevent buildup of foreign matter.

Check lubrication instructions on motor. If oiling is required, add 1 or 2 drops of electric motor oil as follows:

• Light Duty - After 3 years or 25,000 hours of operation

• Average Duty - Annually after 3 years or 8,000 hours of operation

• Heavy Duty - Annually after 1 year or at least 1500 hours of operation.

Check and test the operational functions of all safety devices supplied with your unit.

• Pass
• Flag
• Fail