Blue electronic circuit board with a 3-digit LED display, buttons, and connectors

Kevin Thigpen

Technical Services Manager North Alabama District

September 2, 2021

Furnace Setup Switch

This month I will be covering the Switch Setup on an 80 % Furnace N80VSL Model.


The furnace control board has 4 sets of switches, but some switches may not be used. Below I will outline the function of each switch.



SW1-1: Status Recovery – this option allows the technician to recover the last 10 faults stored in control board. The default for this switch is set to “off”.


SW1-2 & SW1-3 are not used.


SW1-4: Comfort / Efficiency Adjustment- turn on to decrease low heat by approximately 7 % and high heat to around 10%.


SW1-5: CFM Per Ton Adjustment


SW1-6: Component Test – turn on to initiate test mode. The test component will function as follows:


  1. Inducer motor starts and continues to run until step 4 of the component test sequence
  2. Hot surface igniter is energized for 15 seconds, then it is deenergized.
  3. Blower operates for 15 seconds, then turns off.
  4. After component test is completed, one or more status code heartbeat 2 +5 will flash. See component test section of the service manual for an explanation of the status code.
  5. Turn setup switch SW1-6 off.


Note: To repeat the component test, turn setup Switch SW1-6 Off then back on




By following the information in this article, you will have the knowledge to set up the furnace control board switches.

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