Bosch [E29] fault codewhat it means and how to fix it

E29 is the code that names the filters in the water connection of the inlet or AquaStop hose as blocked, and it is one of the few on this platform where BSH publish a full owner procedure rather than a phone number. It is also the code where they attach an explicit warning, and the warning is the reason to read this before you start unscrewing things. AquaStop is a Bosch and Siemens safety inlet hose with an electrically operated valve built into the connector at the tap end, there to shut the water off if the hose fails.

BSH state in terms that because the safety device contains an electric valve, it must not be immersed in water. That rules out the thing people instinctively do with a blocked filter, which is to drop the whole assembly in a bowl and leave it to soak. The blockage itself is undramatic. Mains water carries fine grit and rust, and the gauze screens in the hose connectors exist to catch it before it reaches the solenoid valve inside the machine.

Over several years in a hard water area they silt up until the machine cannot fill within its allowed time. BSH give E29 a second cause alongside the filters — water pressure too low — with a concrete test: about ten litres should come out of the fully open tap in a minute, and if less does, call a plumber. Note how this differs from the general fill code: E29 names the filters and the pressure, where E17 covers the tap, kinks, pressure, the filters and the level sensing together.

1. 1

   Turn the tap off. Bosch’s manual adds a pressure-relief step before you undo anything: select any programme except Rinse, Spin or Empty, start it, let it run about 40 seconds, then switch off and pull out the plug.

   BSH publish an explicit warning on this code: the AquaStop safety device contains an electric valve and must not be immersed in water. Do not put the tap-end assembly in a bowl to soak.
2. 2

   Keep a bucket ready, disconnect the hose from the tap and pour the water left in the hose into the bucket. This is BSH’s order — tap end first.

3. 3

   Clean the filter in the tap-end connector with a small brush. Hold it up to the light: if you cannot see clear light through the mesh it is still blocked, however clean it looks.

4. 4

   If your machine does not have AquaStop — a plain nut at the machine end rather than a permanently fitted hose — also take the hose off the back of the machine, pull that filter out with a pair of pliers, and clean it too.

5. 5

   While the hose is off the tap, run the pressure test BSH give: a bucket under the fully open tap should collect about 10 litres in a minute. Much less than that and they say to call a plumber; no amount of filter cleaning will fix it.

6. 6

   Reconnect the hose by hand — Bosch say hand-tight only, tools damage the thread — turn the tap on and check both connections for leaks before you plug the machine back in.