Heat exchanger assembly Gas manifold
Two−speed combustion air inducer Two−stage gas valve
Main burner cluster Main burner orifices Pressure switch Ignitor
Primary limit control Flame rollout switch Secondary limit
Flame Sensor

Planned Service

The following items should be checked during an annual inspection. Power to the unit must be shut off for the service techni- cian’s safety.

Fresh air grilles and louvers (on the unit and in the room where the furnace is installed) − Must be open and unob- structed to provide combustion air.

Burners − Must be inspected for rust, dirt, or signs of water.

Vent pipe − Must be inspected for signs of water, damaged or sagging pipe, or disconnected joints.

Unit appearance − Must be inspected for rust, dirt, signs of water, burnt or damaged wires, or components.

Blower access panel − Must be properly in place and pro- vide a seal between the return air and the room where the furnace is installed.

Return air duct − Must be properly attached and provide an air seal to the unit.

Operating performance − Unit must be observed during operation to monitor proper performance of the unit and the vent system.

Combustion gases − Flue products must be analyzed and compared to the unit specifications.

Problems detected during the inspection may make it nec- essary to temporarily shut down the furnace until the items can be repaired or replaced.

Instruct the homeowners to pay attention to their furnace. Situations can arise between annual furnace in- spections that may result in unsafe operation. For instance, items innocently stored next to the furnace may obstruct the combustion air supply. This could cause incomplete combustion and the production of carbon monoxide gas.

Repair Parts List

The following repair parts are available through independent Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA International nameplate −− Example: SL280UH070V36A. All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier.

Cabinet PartsHeating Parts

Upper access panel

Blower panel

Top cap

Control Panel Parts

Transformer

Two−stage, variable speed integrated control

Door interlock switch

Circuit breaker

Blower Parts

Blower wheel

Blower housing

Motor

Motor electronics

Power choke (1 hp only)

Motor mounting frame

Motor capacitor

Blower housing cutoff plate

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Lennox International Inc DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE UPFLOW / HORIZONTAL AIR DISCHARGE Planned Service