Testing the Furnace Hotline
What is the Lennox-approved method for testing the heat exchanger of the induced-draft furnace line?
Though AHRI's original "3-Step Heat Exchanger Test Method" has always been successful, when the market turned to induced-draft systems, the three-step method became outdated. The latest approach and the only one approved by Lennox is the 5-Step Method published in the Induced-Draft Heat Inspection Procedure fact sheet.
Here is a brief synopsis of the procedure:
STEP 1: Look for flame disturbances.
STEP 2: Measure carbon monoxide levels in the air stream.
STEP 3: Measure CO levels in flue pipe.
STEP 4: Verify proper installation.
STEP 5: Visually inspect heat exchanger.
Note: This is not the comprehensive test process. Please refer to the written AHRI procedure available from your local Lennox representative or the AHRInet.org website.