Problem with low brew pressure after changing water filter

#1: Post by **Socalsteve** » March 17th, 2013, 5:36 pm

Hi all,

So I just replaced the filter in my filtration system (Duetto is plumbed) and now the pressure only reads around 4 bars. It always read right at 9 before I changed the filter.

And, to make matters more complicated, when I switch to reservoir, it does exactly the same thing.

Thoughts, opinions, etc. would be greatly appreciated. I am sure I am missing something here, yes? What is it?

I know there is a valve to adjust the pressure. Not sure I want to do that yet as there may be something else going on????

As always, thank you all in advance!

Steve

#2: Post by **TomC** » March 17th, 2013, 5:52 pm

It sounds like you've entrained air somewhere into the system. Did you isolate the filter with the line locks (shut off valves) before pulling it? I've used the same plumb in line to bounce between my Duetto II and my Gaggia without this problem.

March 17th, 2013, 6:07 pm

I did do that, I think....I shut off the water before the filter, but not after.

I did just adjust the pressure valve and have it back up to 9 bars. Is there something else I should have done or should do now?

Or, am I good to go?

Thanks!

Steve

#4: Post by **TomC** » March 17th, 2013, 6:20 pm

I think you've managed to bleed out the air that got sucked into the lines when you disconnected. Close off fore and aft of the filter next time and you'll likely be able to avoid this. I imagine it would just take a bit of time to purge thru enough water to eliminate whatever air pocket happened to be there though. One of the perks of plumbing in is you can force water thru the unit without running the pump or even having the unit turned on. I'm not a pump expert by any means, but I believe I've read elsewhere that rotary pumps in particular (like on the Duetto) don't like running dry and can damage them, as opposed to a vibe pump that can tolerate it.

#5: Post by **genovese** » March 25th, 2013, 6:12 pm

TomC wrote:One of the perks of plumbing in is you can force water thru the unit without running the pump ....

Amen. I occasionally travel with my machine and have to switch to the tank away from home, and about one time in five I encounter this failure to prime fully. The symptom is as you said: extremely low output. The first time it happened, I about sh*t myself, because I had a dozen people waiting for coffee. It may be just a matter of giving it time, but sometimes these seem to help:

- turn pump on/off a few times
- rapidly turn bypass adjuster screw in and back out (not all the way out!)
- tap on pump body with a PF handle

#6: Post by **chriscoffee** » March 25th, 2013, 7:36 pm

Most important did you purge the filters by running a couple of gallons of water through them into a bucket BEFORE connecting back up to your machine. You must do that to get not only the air out but also the loose carbon so as not to get it into your machine and possibly plug up any valves.