Sterling Indoor Duct Furnace QVSD-125

Open all disconnect switches and secure in that position before servicing unit

Ensure gas tightness of the safety shut-off valves is checked

Turn off the manual valve upstream of the appliance combination control

Remove the 1/8 inch pipe plug on the inlet side of the combination control

Connect a manometer and note the pressure reading

Turn the manual valve on to apply pressure to the combination control

Is there a loss of pressure indicating a leak?

Ensure no combustible material is within minimum clearance requirements.

Turn off electrical power to the duct furnace.

Open the bottom panel of the furnace.

Compress the spring and remove the main burners.

Clean the inside surfaces of the heat exchanger with a wire brush.

Clean the burners using a wire brush and/or compressed air.