Replacement Harman Black Exhaust Sensing Probe (ESP) for select pellet stoves.
A 3 blink error code means that the control board has not detected the ESP (Exhaust Sensing Probe) at startup or that it lost communication with it while the unit was running.
Also compatible With Eco Choice BA100
Fitment Note: There are multiple colors of ESP probes for Harman stoves. If your stove has a Black, White, or Yellow probe, this black probe is the correct replacement. If you have a Red ESP Probe, you require part 3-20-00844
Harman
You must be careful not to bend an ESP probe if removing it for maintenance purposes. Bending the sheath of the probe will usually ruin the sensor. Likewise, when cleaning your stove, care should be taken to not bend the sensor when cleaning. Do not send brushes or vacuum tools through the stove blindly. Before cleaning your stove for the first time, find the ESP probe and make sure that it is not going to be in the way when cleaning. If it is, remove it from its mount prior to performing work.
Using a 1/4" socket, remove the mounting screw and remove the thermocouple from the stove. Trace the wires back to the control board and unplug the wires.
The Control Board/ESP combination is responsible for all high limit safety control. There are 2 high limits, one normal operation high limit and one backup high limit. The control has an automatic diagnostic circuit that continuously monitors the ESP and Room Sensor for faults. If a fault should occur, the control sends a status alert and at the same time the unit goes down to minimum feed/ minimum burn as a safety condition.
In 2008 Harman changed the ESP probe for all units going forward. The change is notable by the color of the ESP wires, Black wires are Pre 2008 and Red Wires are Post 2008. THESE WERE ROLLING CHANGES AS NEW UNITS WERE MADE AND NOT ALL CHANGES HAPPENED JAN 1 2008.
