Troubleshooting the E-70B Power Switch or Wiring Failure Error Code

Overview

The E-70B error indicates a mismatch between the two contact pairs on the power switch. One pair is a 24VAC input back to the control that tells the system whether the switch is ON or OFF. The other pair is part of the 24VAC heating circuit interlock, ensuring the heating system cannot activate when the switch is OFF.

This error can occur when the wires are mismatched, damaged, or missing.

Call Avoidance Steps

To help the end user resolve the issue without a service call:

1. Power cycle the unit - Turn the power switch OFF.

2. Wait 10 seconds.

3. Turn the power switch back ON.

Field Troubleshooting

If call avoidance steps do not resolve the issue, proceed with the following field troubleshooting steps.

Recommended Parts

CFE 5XX Open Fryer Series

• Power switch

• Wiring harness

• Control

Tools Required

• Multimeter

• Basic hand tools (screwdrivers, pliers, etc.)

• Needle nose pliers

Troubleshooting Steps

1. Inspect power switch wiring.

• If wires are loose or disconnected, reconnect and test.

• If wires are damaged, replace the wiring harness.

• Verify wires are in the correct position (see diagram below).

2. Test voltage across switch contacts.

• Lower control

• With power switch OFF: 24VAC should be present on P12 across Pins 2 (Red-PS2) and 3 (White-PS3) from the control.

• If no voltage, verify 24VAC is present on the P1 transformer connection pins 4 and 5.

• If no voltage, replace transformer.

• If voltage is present, replace control.

• With power switch ON: 24VAC should be present on P12 across Pins 1 (Red-PS1) and 4 (White-PS4) from the switch.

  • If no voltage present, verify connections are in the correct order.

  • Replace switch.

Other Possibilities

• Intermittent wiring faults - Vibration or heat may cause temporary disconnections. Inspect for signs of wear or heat damage.

• Control board input failure - If wiring and switch are good, but the error persists, the control board may not be reading the input correctly. Replace the control board if necessary.