How to Fix Low Pressure/Low Flow on Breville Dual Boiler BES920?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
rintintin
Posts: 3
Joined: 2 months ago

#1: Post by rintintin »

I have an 8-9 year old Breville Dual Boiler BES920 that has been working well until recently. I've had to replace the o-rings a few times over the years.

The issue I'm having now is that I'm unable to pull shots - the pressure gauge stays at zero and there is very little water flow. The hot water flow is also very low. However, the steam wand is still working fine. When I press the 1-cup button, I don't hear the vibration I used to.

The service log showed:

460 x 10 = 4600 shots
8:99 - Coffee Water Flow Failure
10:01 - Coffee NTC Sensor Over Temperature

After clearing the log, it now shows:

8:01 - Coffee Water Flow Failure
10:01 - Coffee NTC Sensor Over Temperature
12:01 - Grouphead NTC Sensor Over Temperature
I've attached a video showing the issue. If anyone has suggestions on potential fixes I could try, I would greatly appreciate it

mangoie
Posts: 68
Joined: 2 years ago

#2: Post by mangoie »

There is only one component that pushes water through the whole system: the pump. So start with that since you dont have any water flow. 8-9 years is a expected lifespan for these Ulka EP5/EX5.

The pumps are not expensive and replacing just take some time and effort, just make sure you have the right voltage.

rintintin (original poster)
Posts: 3
Joined: 2 months ago

#3: Post by rintintin (original poster) »

Even after replacing the pump and upgrading to a brass OPV, my espresso machine is still malfunctioning. When I press the 1-cup button, I only hear a clicking sound from the solenoid valve - the pump does not turn on. The pressure gauge reads 0 bar. Oddly, the pump itself does work; when I drained both boilers and powered on the machine, the pump ran for about 2 minutes before stopping. I've reset the error log and no new codes appear. With these symptoms in mind - the pump not engaging when buttons are pressed, despite being functional otherwise - do you have any ideas what could be causing this? Please let me know if any other troubleshooting details would help diagnose the root issue. I'm happy to provide more specifics as needed.

Replacement pump
Ulka EX5 Solenoid Vibratory Pump 120V 41W - Brass Output
https://www.amazon.com/gp/product/B00B8 ... UTF8&psc=1

symptoms
When I first turned the machine on, the Pump engaged for a few seconds to fill the boiler.

JRising
Team HB
Posts: 3731
Joined: 5 years ago

#4: Post by JRising »

If the pump has proven it can run (You hear it), but it stalls almost immediately (You hear it fail to continue running), then the water path is blocked.

You say that there was Low Pressure, prior to the pump replacement. If the gauge still shows 0 Bar, even when the pump has run the pressure up to the point where it stalls, then the clog is between the pump and the point from which the gauge is reading.

If the gauge is now showing high pressure as the pump stalls, then the clog is after the point from which the gauge is reading.

rintintin (original poster)
Posts: 3
Joined: 2 months ago

#5: Post by rintintin (original poster) »

..

odor4fun
Posts: 52
Joined: 2 months ago

#6: Post by odor4fun »

Try to remove the thermal fuse from the pump, it might work.
If not, the fault is in the triac circuit that controls the pump, it may even be on the electronic board.

If you don't have knowledge of electricity and a voltmeter to measure the voltages on the triac board, it will be difficult to fix it at home.