Frymaster E28

What does Frymaster E28 mean?

The ignition module attempted to establish a burner flame during the trial-for-ignition period, did not detect a valid flame signal from the flame-sensing rod, and entered hard lockout. E28 is a gas-system lockout: the controller logged the failure after the module exhausted its retry attempts. Unlike E25 (blower interlock) or E27 (pressure switch), E28 means air delivery was confirmed but flame was never sensed.

Symptoms

• Display shows E28; burners are cold and no flame is present.
• Ignitor may have clicked during the failed ignition attempt before lockout.
• Oil temperature falls progressively with no heating response.
• Gas odor may or may not be detectable depending on whether the main valve opened.

Common causes

• Gas supply interrupted — main shutoff closed, quick-disconnect not fully seated, or insufficient gas pressure at the manifold.
• Fouled or corroded flame-sensing rod not conducting sufficient microamp current to satisfy the ignition module.
• Failed or weak igniter (spark electrode) not producing sufficient spark to light the burner.
• Defective gas valve coil not opening the main valve despite receiving the ignition module signal.
• Failed ignition module itself, or open high-limit thermostat breaking the 24 VAC control circuit.
• Drain safety microswitch open (drain valve not fully closed) blocking the 24 VAC circuit to the gas valve.

Diagnostic steps

1. 01

   Confirm drain valve is fully closed

   The drain safety microswitch must be actuated for the 24 VAC circuit to complete. Push the drain valve handle firmly to the hard stop. If the handle appears closed but the switch is not clicking, the switch or mechanism requires adjustment.

2. 02

   Verify gas supply pressure

   Check that the main gas shutoff and quick-disconnect are fully open. Measure manifold gas pressure with a manometer — natural gas models require approximately 3.5" W.C.; LP models require approximately 10" W.C. Low pressure prevents the main gas valve from opening fully.

3. 03

   Clean the flame-sensing rod

   With the fryer powered off and cooled, locate the flame-sensing rod in the burner assembly and clean it with fine steel wool or a Scotch-Brite pad. Oxidation on the rod prevents sufficient microamp current flow and causes the module to see no flame even when one exists.

4. 04

   Inspect the spark igniter and cable

   Check the spark electrode for carbon deposits, cracking, or improper gap. The gap between the electrode tip and the pilot hood should be approximately 1/8 inch. Inspect the ignition cable and boot for cracks or arcing damage. Replace the electrode and cable as a set if worn.

5. 05

   Test the gas valve coil resistance

   Disconnect the gas valve wiring and measure coil resistance. Honeywell valves typically read 400–650 Ω; Robertshaw valves 71–75 Ω. An open (OL) or shorted reading indicates a failed valve coil requiring gas valve replacement.

When to call a professional

E28 requires a licensed technician if gas supply pressure is confirmed correct but ignition fails repeatedly, if the gas valve coil is defective, or if the ignition module requires replacement. Gas valve and ignition module work involves combustion system components where improper repair creates a gas leak or fire hazard. Frymaster service: 1-800-551-8633.