Code: E31🧺 Bosch Dishwasher

Bosch Dishwasher E31: Zeolith Drying Heater Fault or E31-00 Leak Protection (Meaning, Causes, Fixes)

Reviewed 2026-10-25 · Based on 6 manufacturer & service sources

What the code means

Bosch France describes error E31 as a problem with the zeolite heating element (résistance zéolithe) on dishwashers with Zeolith drying, which Bosch sells as PerfectDry in Europe and CrystalDry in the US. Zeolite is a mineral held in a tank in the bottom of the dishwasher that absorbs moisture during washing and releases it as heat to dry the dishes; the system is sealed and the zeolite itself never needs replacing. According to Bosch, the code is triggered by moisture in the zeolite tank or by a dirty water sensor, the dishwasher then runs without that heater, and if the code persists after a reset the zeolite heater most likely needs to be replaced. Newer Bosch dishwashers show four-digit codes instead: Bosch USA lists E3100 as the safety switch detecting water in the base of the dishwasher, with the leakage protection system activated, and Bosch Austria and France list E3100 and E31-00 together with E15. That E31-00 code has nothing to do with the Zeolith dryer.

Likely causes

Safe DIY checks

⚠ Before you start

Unplug the dishwasher or switch off its breaker before removing any panels, and turn off the water supply for any leak code. Don't tilt a dishwasher with water in the base. Zeolite heater and internal leak repairs are best left to a Bosch-trained technician.

  1. Read the display carefully. A plain E31 is the Zeolith dryer code; E31-00 or E3100 is the leak protection code. The fixes are completely different.
  2. For a plain E31: turn the dishwasher off and unplug it or switch off its breaker for a few minutes, then restore power. Bosch says this can be enough to reset it. If E31 comes back, book a Bosch service visit, since the zeolite heater sits sealed in the base and usually needs replacing.
  3. For E31-00 or E3100: turn off the water supply to the dishwasher and switch it off. Bosch advises against trying to repair a leak protection fault yourself.
  4. For E31-00 or E3100: look around the base of the dishwasher and along the hoses for leaks, kinks or damage, and check the door seals. A dried leak usually leaves a white limescale trace that shows where the water came from.
  5. Don't tilt the dishwasher to drain water from the base; Bosch warns this risks electric shock or injury. You can bail out standing water in the tub while you wait for service.
  6. If a hose is visibly damaged, replace it with the correct Bosch part for your model; otherwise call Bosch service (US: 1-800-944-2904).

🛠 When to call a pro

  • Confirm the model has Zeolith drying (PerfectDry / CrystalDry) before treating E31 as a drying-system fault.
  • For E31 on a Zeolith model, check the zeolite tank for moisture, clean or check the water sensor, and test the zeolite heating element and its wiring; replace the heater if it is open or the fault returns.
  • For E31-00 / E3100, find the source of the water in the base tray (door seals, hoses, pump, heat exchanger, pressure switch), repair it, dry the base and check the float switch moves freely before reset.
  • Run a test cycle and watch for the code to return before closing the job.

Parts that commonly fix it

Always match the part number to your exact model.

⚙

Dishwasher inlet or drain hose (exact Bosch part for your model)

For E31-00 / E3100 when a hose is visibly kinked, cracked or split.

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⚙

Multimeter

For a technician testing the zeolite heating element on a plain E31.

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⚙

Torx screwdriver set

Needed to remove the kick plate and panels on many Bosch dishwashers.

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Sources

  1. Bosch France: E31 code on a Bosch dishwasher, a problem with the zeolite heating element (moisture in the zeolite tank or dirty water sensor); unplug to reset, likely heater replacement if it persists
  2. Bosch France dishwasher error code list: E31, defective zeolite heating element
  3. Bosch USA dishwasher error codes list: E3100, safety switch has detected water in the base, leakage protection activated
  4. Bosch France: E3100 / E31-00, Aquastop leak protection activated; door seals, drain hose, pressure switch, heat exchanger; don't tilt the appliance
  5. Bosch Austria: dishwasher error E15 / F15 / E3100 / E31-00, water protection system activated
  6. Bosch Singapore: E15 or E3100, safety switch detected water in the base; check base and hoses

Last reviewed 2026-10-25. Always confirm against the manual for your exact model number.