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 (about 10 seconds), 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 show a PV value of _Su1 with a SV value of ON.
6. Press and hold the MODE button (about 3 seconds) until the display shows a PV value of SETn, where n is an integer value, then release the MODE button.
7. Using the UP or DOWN buttons, navigate through the SET menus and press the FUNC button to toggle the SV value from OFF to ON for SET1 and SET2 menus. This will make the key lock, gain correction, and limit settings available.
8. Press and hold the MODE button until the display reads _Su1 with a value of ON, then release the MODE button.
9. Press and hold the MODE button again until the display reads _C/F with a value of OFF, then release the MODE button.
10. Press the FUNC button to change the value to ON. This will make the option to change between °C and °F accessible.
11. 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 a PV value of SET. Use the UP or DOWN arrows to set the SV value to 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 a PV value of SET, then a PV value of _C/F. When you see _C/F, you can release the MODE button.
4. Press the UP or DOWN buttons to change the SV 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 more than 2 seconds. The display should show a PV value of SET. Release the MODE button and then use the UP or DOWN arrows to set the SV value to 2.
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.

NOTE:  In order to prevent unintended changes to the controller, it is recommended that after making the changes above, you follow the steps in Part 1 and Part 2 above to restore the factory settings to lock out access to SET menus 1 and 2 and to restore the key lock setting.