In order to change the factory default of the temperature display setting between °C and °F for the Hakko FR-860 Preheat Plate, the controller must be unlocked and setting limits converted.

CAUTION:  If the setting limits are not converted when making this change, the unit can be damaged.

Part 1 - Unlocking the Controller

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button until the display blinks 1 time, then release the MODE button
4. Press the FUNC button one time and release
5. Press the MODE button one time and release.  The display will read _Su1 with a value of ON
6. Press and hold the MODE button until the display reads SET1 with a value of OFF, then release the MODE button
7. Press the FUNC button to change the value to ON.  THis will make the key lock and gain correction settings available.
8. Press the UP button.  The display will read SET2 with a value of OFF
9. Press the FUNC button to change the value to ON.  This will make the setting limits accessible.
10. Press and hold the MODE button until the display reads _Su1 with a value of ON, then release the MODE button
11. Press and hold the MODE button again until the display reads _C/F with a value of OFF, then release the MODE button
12. Press the FUNC button to change the value to ON.  This will make the option to change between °C and °F accessible.
13. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new settings.

Part 2 - Changing the Key Lock Setting

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button for more than 2 seconds.  The display will show SET with a value of 1
4. Press the MODE button until the display shows _LoC with a value of 3
5. Press the UP or DOWN buttons to adjust the value to 0 which removes the locks on adjusting the controller
6. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new setting

Part 3 - Changing the Display Between °C and °F

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button for more than 5 seconds.  The display will first show SET, then _C/F
4. Press the UP or DOWN buttons to change the RED display value between °C and °F
5. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new setting

Part 4 - Converting the Setting Limits

1. Turn the power on for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button for 5 seconds.  The display should read SET with a value of 2, then release the MODE button.
   NOTE:  If not, press the UP or DOWN buttons until the display reads accordingly.  If the display will not read SET with a value of 2, then the controller is still locked (See Part 1)
4. Press the MODE button one time and release.  The display will read _SLH with a value of either 500 or 260, which corresponds to the maximum temperature setting allowed by the controller (500°F or 260°C).
5. Press the UP or DOWN buttons as needed to adjust the value to correspond with the display setting of either °C or °F.
   IMPORTANT:  Failure to make this adjustment, or setting the level above the maximum values specified in the previous step can cause damage to the unit.
6. After the setting has been adjusted, turn the power OFF on the Hakko FR-860 Preheat Plate to store the new setting.