Bosch wtb86300gb error E90

[Andrew Watson]

Hi,
I have the above fault on my dryer. Any pointers? It seemed to stop for high temp. I’ve checked the thermal fuse on the heater duct- continuity o. I haven’t checked what might be a thermistor that’s mounted next to it.
When I trg to start the dryer there is 5 or so cycles of clicks from the control unit up on the top rhs then it alarms.
Any ideas?

[Andrew Watson]

Continuity ok it should say.

[Paulina]

Hi,

Did you get this resolved, I have exactly the same problem and tested lots of the probable causes.

Exact same fault – On startup a relay clicks 5 times which surges the lift pump each time. Then displays E90 which is a communication error.

I have replaced the lift pump, checked continuity on the pump and level sensor cables. Removed control board and re-coupled all connectors. Checked heater element. Cleaned both lint and moisture sensors.

At my wits end now, last chance is to try swapping the control board, but they are not cheap, so may be better just replacing with a new machine. 🙁

[Bigmac85]

Did you manage to resolve this Paulina? I just got the same error.

[Thien Chau Qui]

Hi, I dried the power board and reconnected all the cables. If the motor cable is removed, it will give e90 for me. So make sure you reseat the motor cable properly

[Author]

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