I have been trying to fix my BDB.
I think the model will be the original 900 as it is over 8 years old.

The problem started with audible steam leaks. Also buzzing when doing a shot.

After taking it apart found evidence of leaking in the steam wand valve, both boilers and the OPV.

After following some advice here I have done the following.
Replaced all the o-rings on the top of the boilers.
Replaced the o-rings on the steam valve
Replaced the steam probes as they were leaking around the ceramic sleeve that holds them in (also replaced the o-rings where they clip in)
Replaced the solenoid
Replaced the OPV

Initially this seemed to fix the problem. The brew pressure was a bit higher at ~10.25 bar but I thought I would leave that and see how it went.

After about 5-10 brews it started leaking again, this time venting into the drip tray. This appears to be coming from the top of the steam boiler.

This has happened a few times before, but only once each time, and letting the machine cool down and heat up solved this (also this was over 6 months ago)

This may be self induced as I did have some confusion replacing the steam probes. I did not realise that 2 of the probes are nearly the same length and may have got them confused. Can someone confirm the Red/Black/Blue to length of probe.

The other thing was what appears to be a thermistor that is held in place by black goo was able to be pulled out without much effort when it was hot. Is this normal ??


any other ideas or tests I can do to troubleshoot this.