The E31 error on your Bosch dishwasher means different things on different models — usually a heat pump fault, a leak-protection trip, or a water supply issue (the latter shown alongside a flashing tap icon). Work through the cheap checks in order before assuming the worst.

Error code E31
Meaning Heat pump / leak protection / water supply (model-dependent)
Severity Medium — DIY for water and leak checks, technician for heat pump
Time to fix 15–60 minutes
Tools needed Towel, soft brush, T15/T20 Torx

What the E31 error means

Bosch uses E31 across several diagnostic paths. The most common interpretations: a heat pump fault on heat-pump models (the part that warms wash water on newer Bosch machines), a leak-protection trip when water is detected in the base pan, or a water supply issue when shown with a flashing tap icon. Look at the display first — the tap icon narrows it down to supply, no tap means heat pump or leak.

Common causes

  • Faulty or scaled temperature sensor on the heat pump
  • Damaged or blocked heat pump itself
  • Water collected in the base pan triggering leak protection
  • Damaged inlet hose (e.g. mice chewing through pipework)
  • Faulty water inlet valve
  • Damaged wiring or control board fault

How to fix the E31 error

  1. Reset the dishwasher. Unplug for a few minutes and plug back in. A control glitch sometimes throws E31 once and clears on the reset.
  2. If a flashing tap icon shows with E31, the fault is the water supply. Check the inlet hose for kinks or damage, confirm the supply valve is fully open, and inspect the inlet valve for blockage.
  3. Drain the base pan. Tip the dishwasher backwards by about 45 degrees so any water in the base pan drains off. Remove the kickplate (T15/T20 Torx), confirm the pan is dry, and check internal hose connections for drips.
  4. Clean the filter and check the drain hose. Twist out the circular filter, rinse, refit. Confirm the drain hose at the back isn’t clogged or kinked.
  5. If E31 returns after all checks, the heat pump itself or its temperature sensor has likely failed. That’s a Bosch-trained technician job — heat pump replacement isn’t a typical DIY repair.

FAQ

What does the red tap icon next to E31 mean?
The flashing tap icon shifts the diagnosis to the water supply. Check the inlet hose, supply valve, and inlet valve before looking at heat pump or leak protection.

Can I run the dishwasher with E31?
No — depending on which fault it points at, running the cycle risks either water damage (leak protection trip) or heating failure. Diagnose first.

Why are there so many possible meanings for E31?
Bosch reuses some codes across model ranges, especially between machines with and without heat pumps. The display variant and your model number narrow it down — check the model badge inside the door before searching deeper.