What E:31 Means
E:31 means liquid water has reached the zeolite container. Bosch is blunt about the consequence in this row: water ruins the zeolite granules and the container has to be replaced, and the water sensor that detects the problem is built into the container so it cannot be swapped on its own. The listed causes are overfilling through a faulty inlet valve, excessive foam, and water left in the machine when it was tilted or laid down for a previous repair.
Common Causes of E:31
- Overfilling through a faulty water inlet valve
- Excess foam from the wrong detergent or overdosing
- Water left in the machine when it was tilted or laid down during earlier work
🔧 One Safe Check You Can Try
Check your detergent and rinse aid dosing, because Bosch names excess foam among the causes. Using ordinary washing-up liquid in a dishwasher generates exactly the foam volume that gets water where it should not be.
⚠ Why You Shouldn't Go Further Than That
- One documented cause is a machine that was tilted for a previous repair without vacuuming the water out first, which is why Bosch tells technicians to block up only the right side of a zeolite machine.
- The water sensor is sealed inside the container, so there is nothing to clean, test or dry out.
- Continuing to run cycles while the container is wet keeps feeding the damage that has already started.
- If a passing inlet valve is filling the machine when it should not be, the same fault can flood the cabinet, so the water supply is worth closing.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.