Hi! I'm having trouble with my BES920

It started with a leaking steam wand, I've replaced that and no more wand leaks.

I did notice some signs of water damage with corroded screws etc and discovered a small leak on the steam boiler.

I've repaired the leak, but I still have an issue with runaway heating. The temp just keeps rising and the machine never becomes usable.

Is the machine done for? Is there another part I could look at replacing?

look at the bdb repairs and mods thread here. This issue can be caused by steam leaking and damaging the control board. Make sure you take the top off and let everything dry completely for a couple of days. Try that and if it worked you need to find the leaky o ring in there and replace it. Easy enough fix

Thanks for the tips.

I've had the lid off for two days now, still have issues. Should I bother replacing the board? Or is it likely a different issue? Or just wait longer and cross my fingers?

It might be worth reaching out to pcrussell50 on the bdb mods thread for his advice. He's the bdb guru

Moolk wrote:Hi! I'm having trouble with my BES920

All espresso machines eventually need attention. You issue is one of the common ones when the high current, heater control board mounted to the underside of the top cover gets wet from a steam leak. You can verify this by propping up the top cover so that the high current board is away from the steam boiler and is fully dried out. If it's very wet, unplug the machine and remove the plastic protective grate over the board, inspect for moisture, point a fan at it for a few hours, make sure it is TOTALLY dry. Then, with the cover still propped up and open, warm up the machine. If it's bone dry, you should no longer get runaway heating.

Moolk wrote:It started with a leaking steam wand, I've replaced that and no more wand leaks.

Interesting. Usually, you have to replace the steam valve, or preferably re seal the steam valve, since it is of a design that is serviceable and need not be thrown away. The wand is not usually the source of leaks. Could you describe more?

Moolk wrote:I did notice some signs of water damage with corroded screws etc and discovered a small leak on the steam boiler. I've repaired the leak, but I still have an issue with runaway heating. The temp just keeps rising and the machine never becomes usable.

If this is what you did: Diagnosing leaks by looking at mineral deposits alone is not the preferred way to diagnose leaks. You can miss them that way. The best way is by wiggling the tube with the top cover open, and looking closely for hissers. What size o-ring did you use? What composition? Silicone? EPDM? AFLAS? Nitrile and Viton will not last long but will work for a short while. Also, even if you used one of the first three, if you used size -006 like some people think they need, the seal will be short lived. You need -007. Finally, there are the three water tubes on TOP of the steam boiler, AND a harder to reach one on the side. This one has been the source of steam wetting down the heater control board. You should do a wiggle test on all of them to rule out or repair hissers.

You should bookmark this page: Breville Dual Boiler Mods and Maintenance

-Peter

pcrussell50 wrote:
Interesting. Usually, you have to replace the steam valve, or preferably re seal the steam valve, since it is of a design that is serviceable and need not be thrown away. The wand is not usually the source of leaks. Could you describe more?

Yes, apologies, I meant to say "replaced the valve"

Since the valve is serviceable, hopefully you kept your old leaker around to service it and put it back into use when (not if, but when), the new one leaks again.

-Peter

Update. Finally got around to replacing the o-ring on the side of the boiler. I can still hear a hissing sound and I can get a spoon to steam up. It's either coming from under the boiler, or the boiler itself has a hole in it... are they replaceable?

It seems I also now have the opposite problem. With the machine not reaching temperature.