Alto-Shaam E88

What does Alto-Shaam E88 mean?

E88 is an ignition failure fault on gas-model Alto-Shaam Combitherm ovens. The ignition control attempted to light the burner but the flame sensor did not detect a sustained flame within the trial-for-ignition period. The gas valve closes and the oven locks out to prevent unburned gas accumulation. This code applies to the primary (upper) burner on dual-burner models.

Symptoms

• Oven shuts down and displays E88; no cooking heat is produced.
• No click from the igniter or no glow from the hot surface igniter (HSI) during startup.
• Igniter activates but burner fails to light, confirmed by no flame visible.
• Error recurs within two restart attempts, triggering a hard lockout.

Common causes

• Hot surface ignitor (HSI) failed — cracked, open circuit, or wrong resistance (normal range: 40–60 ohms).
• Gas supply shut off at the wall or appliance shutoff valve.
• Gas pressure outside the specified range for the oven model.
• Flame sensor (rectification rod) coated with oxidation or debris, preventing microamp signal.
• Faulty gas valve not opening on command from the ignition control.
• Defective ignition control module.

Diagnostic steps

1. 01

   Confirm gas supply is on and pressure is correct

   Verify the manual gas shutoff valve at the wall and at the oven appliance connector are both fully open. Measure gas pressure at the manifold with a manometer and confirm it matches the rating plate specification for natural gas or LP.

2. 02

   Inspect gas hose and quick-disconnect connections

   Check the flexible gas connector and quick-disconnect fitting for proper seating, kinks, or signs of damage. A partially connected or kinked connector restricts gas flow and prevents ignition.

3. 03

   Test the hot surface ignitor resistance

   With power locked out, disconnect the HSI leads and measure resistance across the ignitor. The correct resistance is 40–60 ohms at room temperature. An open reading (OL) or a reading outside this range means the HSI is failed and must be replaced.

4. 04

   Clean and test the flame sensor

   Remove the flame sensor rod and clean the tip with fine steel wool or emery cloth to remove oxidation. Measure the microamp (µA) signal back to the ignition module during a light attempt; the signal must meet the module's minimum threshold to confirm flame.

5. 05

   Attempt restart — maximum two times

   After addressing gas supply and HSI/sensor checks, restart the oven. Alto-Shaam documentation specifies: if E88 persists after two restart attempts, remove the oven from service immediately and contact an authorized service provider. Do not attempt further restarts.

When to call a professional

E88 that persists after two restart attempts is a mandatory service call per Alto-Shaam's service procedure. Gas ignition diagnosis — particularly gas valve testing, manifold pressure measurement, and ignition module replacement — must be performed by a technician certified to work on commercial gas appliances.