Pellet Tech 101 – Harman Control Board Status Light and Error Codes

Welcome Back to Pellet Tech 101!

Most Harman pellet and corn stove models will have a control board that has a status light. The status light is designed as a troubleshooting tool indicating areas that need to be addressed through blink sequences. There have been several control/circuit board versions and variations over the years with Harman; your best reference for status light error codes will be the owners manual that came with your appliance.

The 4 Output Platinum Control Board, part 3-20-05374, 1-00-05886 is the most common Harman replacement control board. This control board is correct for the Harman Accentra 52I, Accentra FS (Accentra Cast), Accentra Insert, Advance, P35I Insert, P43, P61A, P68, XXV (25th Anniversary Model), and Mark I coal stove. Harman’s most current platinum control board will have the following status light blink sequences.

1 Blink: Indicates a control board self diagnostic failure. This requires a manual reset*.

2 Blinks: Indicates an open vacuum switch error. This requires vacuum switch inspection and replacement if faulty.

3 Blinks: Indicates E.S.P. (exhaust sensing probe) failure. This requires a manual reset* and ESP probe cleaning and replacement if faulty.

4 Blinks: Can occur only in Room Temp Mode and indicates Room Sensing Probe failed or not installed. If a Room Sensing Probe is then installed, the status light will automatically reset. In PF100/PF120 furnace models, this only occurs in automatic mode. Indicates the wall control thermostat has failed or is not installed. If the wall control is then installed the error will automatically reset after the furnace warms up. Note: The furnace will not start in “auto” with this error status.

5 Blinks: (In Igniter Auto Mode Only): Indicates that the unit has failed to light within the 36 minute start cycle. For PF100/PF120 furnace models, this indicates the unit has failed to ignite after 4
consecutive 8 minute attempts. To reset – Turn Mode Selector to “OFF”, then turn to either mode again. We recommend thorough cleaning of the burnpot, burnpot holes, burnpot igniter area, and igniter OHM check.

6 Blinks: Indicates that the control board has calculated poor or incomplete combustion occurring for more than 25 minutes. A six blink status may be set if the stove is allowed to run out of pellets. To reset, turn mode selector to “OFF” then back on to the desired mode. If the unit was not out of pellets, further troubleshooting will be required.

7 Blinks: Only applicable on the PB105 and HF60 boiler control boards. Indicates water over-temp. Reference your owners manual for common causes and solutions.

* Manual reset – disconnect power cord for a few seconds and reconnect. If error still occurs leave us a comment or contact us.

If you would like to learn more about your Harman control board settings or if you need to replace your Harman control board or set the dip switches on the control board, please see our reference videos below.

Browse Harman Control BoardsBrowse parts by make & modelLooking for a better way to clean? Browse ASH VACUUMSAny Further Questions or Technical Assistance Needed Please Leave us a Comment Below.


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