VERIFIED
The knock at fill time
Some kitchens announce each fill with a thump from the wall or under the sink. It happens when the inlet valve closes quickly and the moving water has nowhere to go, a plumbing effect commonly called water hammer. If it is audible and E35 shows around the same time, the two may be related, or may just share a cause. The inlet valve opens to let water in and shuts to end the fill, so the closing moment is when a knock is most likely to be heard.
Where E35 stands
Bertazzoni does not give one confirmed meaning for E35 across all dishwasher models, so this page does not claim one. The sound simply adds to the evidence about the fill stage.
Things that can add to it
- High water pressure at the building, which varies from street to street.
- Loose pipes that rattle against joists or studs.
- A shut-off valve that is only partly open.
- An old, stiff supply hose.
What owners can safely do
Listen to the fill and note whether the knock comes at the start or at the stop. Fully open the shut-off valve under the sink and see if the sound changes. Check whether other fixtures, such as the washing machine, knock the same way. If so, the cause is probably the house plumbing, not the dishwasher.
Do not tighten any fitting while the line is pressurized, since a small turn can turn into a drip.
Who fixes what
Repeated hammer is a plumbing issue and a plumber can add an arrestor or a pressure regulator. If the pipes are quiet and E35 continues during the fill, the dishwasher side comes next: the inlet valve, the level sensing and the control connections, which a technician tests with the unit open.
Mention the sound when you call, since it changes the order of testing. A visit includes diagnosis and a written estimate, and no part is replaced without your approval.
Long-term view
Pipe knock wears fittings over time, so it is worth addressing even if the dishwasher turns out to be fine.
Information for the visit
Note the age of the building, whether pressure feels strong at the other taps, and whether knocking occurs elsewhere. If you hear it only with the dishwasher, say so. That detail steers the first test toward the fill valve and its mounting rather than the building pipework. A knock only at the end of the fill matches the moment the inlet valve closes; a rattle during the whole fill points more toward loose pipes.
Frequently asked questions
A shock in the pipes when flowing water is stopped suddenly, usually by a valve closing.
It is better to address it, since repeated shocks can loosen fittings.
No. It often points to the house plumbing.
Model compatibility: Bertazzoni reuses codes across series and model years, so E35 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
