Replacing High Limit Thermocouple

Follow these instructions to replace the high limit thermocouple for the PFG 690, 692, 691 and OFG 390, 392, 391.

Only perform this procedure when the unit is cool or severe burns may result.

Preparing Fryer

1. Turn power switch off.

2. Ensure fryer is cool to the touch before moving.

3. Pull out the fryer and unplug from power source.

4. Drain oil to filter pan.

Removing High Limit Thermocouple

1. Lower the control board, disconnect wiring, and set aside.

2. Remove the four thermocouple wires from the high limit control.



3. Remove the three screws (5/16" hex) from the high limit thermocouple bracket.



4. Loosen the compression fitting (1/2" wrench).

5. Remove the high limit bushing (11/32" crowfoot wrench).

6. Remove high limit thermocouple and discard.

7. Clean the high limit brackets and the threads of the fitting in the vat.

Installing New High Limit Thermocouple

1. Insert high limit thermocouple into vat.

2. Apply Loctite^® 567 (white pipe thread sealant) to the high limit bushing and tighten to 32 inch-lbs (3.6 Nm). Do not tighten the compression fitting yet.

3. Install the high limit probe into the three mounting brackets on the burner tube. Leave 1" from the tip of the probe to the end of the bracket and 1 1/4" from the probe to the vat wall and tighten the three screws, shown in image above.

4. Tighten the high limit compression fitting. Finger tighten this and then turn 1/2 turn, shown in image above.

5. Connect both pair of thermocouple wires to the high limit module.

   • Connect one pair to TC1 and one pair to TC2.

   • Red wire connects to the (-) terminal and white wire connects to the (+) terminal.

6. Secure wires with zip ties to leave wiring neat and clean.

Installing Control Board and Test

1. Re-install control board ensuring all connections are secure.

2. Plug in fryer.

3. Fill vat with oil and test.