Hello.

This is a factory unmodified Dual Boiler.
Preinfusion is set for 7 seconds and at 60% pressure.
This has been happening since a little more than a month.

I start the extraction, there is a little flow of water like if a valve opens but with no real pressure and the pump remains silent. At 7 seconds the pump kicks in.

If I do it after the pump has already worked at full pressure at least one time the preinfusion works regularly. For this reason what I usually do, first I press the single espresso button and keep it pressed until the pumps starts working (usually immediately or after a couple of seconds, however sometimes I have to press it more then once). Then I insert the portafilter and make my espresso, without any issue.
If I have to make a second espresso, I do not need to do the first step.

In short it is like I have to wake up the pump at least one time before the machine can work properly.

Things do not change if I unplug the machine or if I do the hard reset.

Any thought about what it is happening?
http://www.youtube.com/watch?v=EtgxEVwqWDg

(sorry for the background noise, they are fixing my HVAC...)

Thanks for uploading the vidy. Makes it easier to understand what is going on. Have you opened the top to see if there are any leaks? Anytime there are these weird, seemingly electronically caused problems, steam leaks should be the first consideration. Open the top. Look for leaks. Then leave the top open for a few days to let the machine dry out. If nothing changes after a few days, I would change out the pump. It is cheap and relatively easy. If that doesn't work, I don't know.

One last question comes to mind. When the 7 second delay is happening, does the machine make a gurgling sound?

Good luck, god speed and don't get electrocuted.

Thank you gentlemen.
I have not opened the machine yet. I'll have to see how that is done.

To answer the first question, it happens with all the three buttons. I have uploaded a new video to show it.

Regarding the gurgling sound, if the machine has been sitting there for some time, you can hear it for maybe a second while a small amount of water is released. After that there is only a humming noise. If you increase the volume to the max you can probably hear them.
As you can see it is really like I have to run the pump at full pressure at lest one time, after that the preinfusion works properly, no matter how many espressos I extract.
The espresso still tastes great, but it is definitely an odd behavior.

Before posting I did a search on the forum but I did not find anything relevant.

However I have just "googled" the issue and actually found two topics about the same problem:

Breville BES900XL won't preinfuse?

Pre infusion not working on Breville Dual Boiler BES920

It looks like it this problem is more common than I thought.

Bad news...your pump is on its last leg. Mine did the same thing. You can buy some time by priming the pump at full power for a few seconds, then attach PF and proceed like normal, or up the preinfusion power to where the pump will actually work. If I'm right (and I hope I'm not) it's going to fail for good one of these days. Good news though, a new pump is not expensive and replacement is somewhat easy, but time consuming. If you really like the BDB, like me, do the pump replacement. Plus...it makes you feel like a real espresso machine repairman!!

BaristaBob wrote:Bad news...your pump is on its last leg. ...

I think I am going to order one.

Do you know which one is the the right pump?

https://www.amazon.com/Ulka-EAP5-Vibrat ... B00NMNA138

https://www.amazon.com/gp/product/B08PCBG2FV/

I tried to find the right one at eReplacement parts but I could not find it, however if they have it I may buy the Solenoid Valve and the Collar Insert as well. They were among the parts that were recommended to me to keep as spares, just in case....

https://www.ereplacementparts.com/solen ... 30650.html

https://www.ereplacementparts.com/colla ... 10640.html

Bought mine through Amazon. Here is the link.

https://www.amazon.com/Model-120v-minut ... C87&sr=8-1

Thanks. Ordered it.
BTW, I increased the preinfusion to 65 and so far, today it has never happened. It may be a coincidence, we'll see.

I thought this thing was smaller and lighter. Nice.
I'll keep it aside with the solenoid valve until the current ones stop working.

Regarding the running at 65% pressure and working fine, it must have been a random thing. It did not work anymore.
Now before pulling a shot I just open the dispenser for the hot water for a second and then I pull the shot.