Troubleshooting an E-22 No Heat Error Code

Overview

E-22 – No Heat is generated when the controller detects that the heating system has been energized, but the vat temperature does not increase as expected.

This monitoring feature checks the heating system once per second and compares heat-on time to the actual temperature rise.

Heat Monitoring Logic

Cold Oil Condition

• Monitoring starts when the vat temperature is 120°F (49°C) or below.

• The controller expects a 30°F (16.7°C) temperature increase.

• If a 30°F (16.7°C) rise occurs, the monitoring period resets.

• If a 30°F (16.7°C) rise is not achieved within:

  • 7 minutes of monitoring time, and

  • 3.5 minutes or more of accumulated heat-on time, the controller generates an E-22 error.

Warm or Hot Oil Condition

• Monitoring starts when the vat temperature is above 120°F (49°C).

• The controller expects a 30°F (16.7°C) temperature increase.

• If a 30°F (16.7°C) rise occurs, the monitoring period resets.

• If a 30°F (16.7°C) rise is not achieved within:

  • 5 minutes of monitoring time, and

  • 2.5 minutes or more of accumulated heat-on time, the controller generates an E-22 error.

Call Avoidance Steps

Before dispatching a service technician, have the customer perform the following checks:

1. Verify that the fryer is powered on and not displaying additional error codes.

2. Confirm that the gas supply valve is fully open.

3. Verify that the facility gas supply is available and other gas appliances are operating normally.

4. Check that the fryer is calling for heat and the setpoint is above the current vat temperature.

5. Cycle power to the fryer and allow the unit to attempt a normal heat-up cycle.

6. If E-22 occurs repeatedly after these checks, schedule a service visit.

Field Troubleshooting

Troubleshooting Steps

Verify the Error

1. Confirm that the displayed error is E-22 – No Heat.

2. Clear the error and start a normal heat cycle.

3. Observe the fryer operation.

If the burners ignite and temperature rises normally, monitor operation and check for intermittent issues.

If the error returns, go to Verify Heat Demand.

Verify Heat Demand

1. Check the displayed vat temperature.

2. Verify that the temperature set point is higher than the actual temperature.

3. Confirm that the controller is requesting heat.

If the controller is not requesting heat, troubleshoot the control system before continuing.

If the controller is requesting heat, go to next step.

Check Burner Operation

1. Observe whether the ignition sequence begins.

2. Listen for ignition attempts and gas valve operation.

If the burners ignite and remain lit, go to Verify Temperature Rise section.

If the burners do not ignite, go to Verify Gas Supply section.

Verify Gas Supply

1. Confirm that all manual gas shutoff valves are open.

2. Measure incoming gas pressure according to equipment specifications.

3. Verify that facility gas service is available.

If gas pressure is missing or below specification, correct the gas supply issue and retest.

If gas pressure is correct, go to next step.

Check Main Gas Valve

1. During a call for heat, measure for 24 VAC at the main gas valve coil.

2. Compare measurements to the unit wiring diagram.

If rated voltage is present but the valve does not open, replace the main gas valve coil or gas valve is coil is good.

If rated voltage is not present, troubleshoot the ignition circuit, controller output, and wiring.

3. After repairs, retest the fryer.

Verify Temperature Rise

1. Start a heat cycle.

2. Measure actual vat temperature using a calibrated thermometer.

3. Compare the measured temperature to the controller display.

If the vat temperature rises at least 30°F (16.7°C) during the monitoring period, the heating system is functioning correctly.

If the burners operate but temperature does not increase properly, go to next step.

Check Temperature Probe

1. Inspect the temperature probe for damage or contamination.

2. Compare displayed temperature with an independent thermometer.

3. Check probe resistance or signal according to service specifications.

If the probe reading is inaccurate, replace the temperature probe.

If the probe is operating correctly, go to next step.

Inspect Wiring and Control Components

1. Inspect all heating circuit connectors and wiring.

2. Check for loose, damaged, or corroded connections.

3. Verify controller outputs during a heat call.

If wiring problems are found, repair or replace the affected wiring.

If wiring is good but outputs are incorrect, replace the controller or failed control component as required.

Final Verification

1. Clear all errors.

2. Perform a complete heat-up cycle.

3. Verify that:

   • Burners operate correctly.

   • Temperature rises normally.

   • No E-22 errors return.

If the fryer completes a full heat cycle without faults, return the unit to service.

Other Troubleshooting

Intermittent Gas Supply Issues

A facility gas regulator problem or fluctuating gas pressure may cause occasional E-22 errors. Monitor gas pressure over time if no component failure is found.

Partially Restricted Burners

Dirty or restricted burners may ignite but produce insufficient heat, causing the fryer to fail heat-rise monitoring requirements.

Temperature Probe Drift

A temperature probe that is only slightly out of calibration may cause false E-22 errors even though heat is being produced.

Wiring Connection Issues

Intermittent loose connections between the controller, ignition system, and gas valve can cause sporadic heat failures that are difficult to reproduce.