Breville Dual Boiler (BES920XL) issues

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by CortadosAreMyJam »

Hi there,

I have a Breville Dual Boiler (BES920XL) with a few issues and wanted to get some feedback. My questions are related to brew pressure on the gauge and water leaking.

1. Brew pressure: When testing out the machine's pressure, I place the silicone cleaning disk into the 1 Cup Dual Wall 58mm Filter and run the machine on manual for 30 seconds. The pressure goes up to 9 bars and stays there until I stop the brewing. Is this pressure level normal for a cleaning disk pressure test?

2. Leaking water: I notice that sometimes when preforming the above test, that there is close to 2 or 3 tablespoons of water underneath the drip tray on the left half of the machine. What would be causing this leak?

3. Today I removed the top and back cover and successfully replaced the o-rings (9 in total) on the brew and steam boiler, put the machine back together and did not see a difference in brew pressure and it did leak water on the left side under the drip tray. If the o-rings are no the issue, what could be causing this leak and slightly low pressure?



#2: Post by BaristaBob »

Not sure anything is wrong with your BDB. If your OPV is set to 9 bars then using a blind screen will cause the pressure to rise and stay at 9 bars until you press stop. The water in the tray is the back flush water from the three way solenoid valve doing its job to release pressure once you pressed stop.

Edit: oops, I read your post wrong, so if water is under your tray (not in the tray), you might be "spilling" a slight amount of water out of the tray itself when removing it.
Bob "hello darkness my old friend..I've come to drink you once again"


#3: Post by cmin »

Sounds like it's working fine, normal for any machine, I have bass pump and opv mod and have set at 8 bar max. If I did what you did it would just stay at 8 bar as that's where the pressure will be with blank disk (or puck, obviously puck will have degrading pressure).

As for the water, the tray is super sensitive especially if filled up higher. If it's slightly off or if you don't carefully pull the tray it'll spill, the left drip part that catches the water from the valve easily flows over with movement. I even removed mine today like normal to clean and spilled water inside it, like always lol

CortadosAreMyJam (original poster)

#4: Post by CortadosAreMyJam (original poster) »

Since my initial post, here is what I discovered with my Breville Dual Boiler:

1. Leaking water: The machine has been off for the week or so, but yesterday I brewed 2 cappuccinos with success. After brewing, I emptied the portafilter and drip tray. I turned off the machine and turned the steam knob all the way open to let the machine blow off steam for a minute or two. I did not put the drip tray back, as it was drying on a drip mat.

Then, I noticed water leaking from inside the machine on the right side where the drip tray usually would be. I placed a small microfiber towel to catch the dripping water. After about 30 minutes the towel was quite soaked. Also, I noticed a small amount of moisture around the steam knob.

What would be causing this type of leak?

Thank you for your help


#5: Post by seang »

Sounds like a leaking oring on the steam circuit. You'll need to pop the lid to see which one


#6: Post by bluesnote »

Seems I have the same dilemma :(

I've attached pics to show where the leak can be seen, I can still use the machine and it appears to be working perfectly. I've removed the top/back and everything looks bright shiny and clean with no visible evidence of leaks. Nothing shows at the two boilers/ steam valve/ pumps or flow control. Everything visible is clean and dry.

After use, the leak appears as in pics, when left overnight the pooling would be around 500ml or more onto the bench- I now place microfiber cloths around the base to adsorb the pooling.

The second pic shows pooling after around 5 minutes.

Any thoughts on where to look, this is only a recent development?

Thanks in advance


#7: Post by bluesnote »

Further to my above post. . .

I have removed the bottom of the machine and found the leak, the hose that delivers water from the tank has rubbed through.

Can anyone tell me where this hose ends? For the moment my fix would be to remove the outer valve part and try to insert a hose over the split line and try to reconnect using cable ties (very tight access). If I could trace the split hose the ideal would be to replace. . .

Thanks in advance


#8: Post by bluesnote »

Further, further to the above. . .

Removed another 8 screws which allowed me to remove the internal base - I was then able to get clear access to the split hose.
Cut the split/damage off and was able to reconnect the tank line barb back onto the remaining hose.

I need a small cable tie to make the join seal and permanent, but my leak is fixed whooHooo 8)

Tomorrow I'll pick up some cable ties and see if I can remember how to put her back together - Coffee o'clock is calling :D



#9: Post by bluesnote »

Just a final on my leak. . .

I noticed two more removable panels so out with the screwdriver again.

The larger panel that reveals the boiler drains gives excellent access to the split hose making my repair very straight forward.

Fitted the cable tie and put the machine back together, no left over screws (always a good sign) and set up to brew a shot - felt like a comforting milk drink and wanted to ensure both boilers were filling/heating and no leaks. I had already done the steam wand hack (reversing the washers) and fitted all new 'O' rings to steam and brew boilers.

All good, the nasty leak is no more, no leak from the steam wand - treated her to a new group seal and good clean 8)

I owe a big thanks to HB and those that have contributed images of their various problems and fixes, I scoured the forum for pics showing how to get access to deal with my issue and found them very helpful. Hopefully others will now benefit from my effort too.