Izzo Alex Duetto 3 - no brew pressure / PID switches off

#1: Post by **sinterklaasje** » August 5th, 2014, 9:56 am

Hi all,

I'm a new registree to this forum - yet I've been reading a lot in the background over the last so many months. I've found the information very helpful and I've learnt a lot about the basics of espresso/cappuccino, after which I started trying out stuff for myself.

Part of this journey for me has been to buy a new machine and matching grinder a bit over 2 months ago. An Izzo Alex Duetto 3 (latest model) and a Mazzer Mini Type A (stock burrs for now). Also part of the journey has been to try different types of coffee to find what we like best, grind setting, tamp pressure, brew temperature...and brew pressure. I am sure if you are familiar with the Alex Duetto, you will know that the brew pressure can only be changed if you remove the shell and adjust using the 'screw' on the left hand side of the machine next to the rotary pump. If you don't know how to do so, I've written a brief description (including photo's on another - Dutch - forum) - I can share the link.

I have changed the brew pressure (from 11+ Bars -> 9-9.5 Bars) and the machine continued to operate (explained in the Italian section of the owner's manual, not in the English/German translation). Until last week, the pump pressure completely dropped to below 2 Bar. I may have to add that I use the reservoir with filtered water (Brita - am aware of the water filter discussions

). I've been in contact with the Dutch (reputable and physical) store where I have bought the machine and they told me that I should reset the brew pressure to its original setting and try again (as 11bars was perfectly fine for this machine........) ... to no avail (I've tried)..... I've posted some videos online that might provide some additional insights:

Video showing problem (when it occurred last weekend - still with adjusted brew pressure 'screw'):

Video showing problem (now brew pressure 'screw' dialed back to original setting):

Do you know what the problem (and solution) could be? Is this a known issue?

The second thing I am running into (but I read everywhere this is 'normal') is the following: when I draw a glass of water from the boiling water tap on the right - the PID 'shuts down' for approximately 10 seconds and connects again. The machine makes a noise as if pressure is increasing - and this seems to be confirmed on both dials. Again - my machine is connected to the reservoir. What I do not understand why the PID shuts down, the steamboiler is dropping so drastically (I am aware I am using the steamboiler for the boiling water) and why the brewboiler pressure is increasing and then dropping again....

Video showing 'PID shut down problem' :

Your help on both topics above is much appreciated.

thanks & best regard,
Mischa

#2: Post by **DaveC** » August 5th, 2014, 12:46 pm

A lot of information there, but a ton of questions and confusion as well. first lets cover the brew pressure problem. Without any context it's difficult to know what's going on and there could be lots of problems causing low brew pressure so we need to simplify to find the problem.

1. Check your brew pressure against a blind filter. See what it reads against a blind filter.
2. If it's still really low...check the tube from the expansion valve isn't venting like crazy into your drip tray

I say all this because the Gicleur in the group is 0.7mm and even without a portafilter in offers enough flow restriction for pump pressure to show as 9 bar. If your not getting decent pressure a very slack expansion valve would cause this problem....is your drip tray filling fast, because I believe that's where the expansion valve vents.

I don't remember the PID flipping off when the steam boiler needed refilling in the last Duetto I reviewed (same model as yours or later. However, it might if the machine is set to steam boiler priority.

I assume in the Netherlands you are in simultaneous boiler operation. F02 = 5

August 5th, 2014, 1:15 pm

Hi Dave,

thanks for the swift reply. I tried to pack as much info into the post as possible - but can imagine that it's not sufficient. To address your points:

1. The brew pressure was measured with a blind filter in the last video. So when engaged it's between 1.5 - 2 Bars.
2. I'll need to check the tube of the expansion valve... not even sure where that is located - but can look that up. I do notice (from the beginning) that there was a dripping stain in the drip tray. Not where the backflush comes up, but more to the left and on the 'edge' of the dripping tray. Not sure whether that has anything to do with it though.

I wouldn't say my drip tray is filling fast - but not sure how 'fast' is defined.

I have left the PID at default (F02) setting for the moment - but have wondered whether I shouldn't simply turn on the simultaneous operation - this should normally not be a problem for the electricity network.

#4: Post by **DaveC** » August 5th, 2014, 1:55 pm

sinterklaasje wrote:1. The brew pressure was measured with a blind filter in the last video. So when engaged it's between 1.5 - 2 Bars.

2. I'll need to check the tube of the expansion valve... not even sure where that is located - but can look that up. I do notice (from the beginning) that there was a dripping stain in the drip tray. Not where the backflush comes up, but more to the left and on the 'edge' of the dripping tray. Not sure whether that has anything to do with it though.

I wouldn't say my drip tray is filling fast - but not sure how 'fast' is defined.

I have left the PID at default (F02) setting for the moment - but have wondered whether I shouldn't simply turn on the simultaneous operation - this should normally not be a problem for the electricity network.

PID, use simultaneous operation, why would it be a problem in the Netherlands

The drip tray would fill pretty fast if excess pressure is venting from the expansion valve, when pulling a shot against a blind filter. It's the littile tube a few cm to the left of the group vent at the back of the drip tray. Usually only a few drops or very little comes out during and after a shot 5-10ml. if your seeing a good flow of water from this tube, this could be your problem.

If not, then you need to check that you screwed the bypass valve on your pump in the correct direction...you need to turn it clockwise to increase the pressure. It's an acorn nut with a slot head screw in the centre. Turn the slot head screw clockwise and adjust with the machine running.

August 5th, 2014, 2:23 pm

I've checked the drip tray - there does not seem to be a problem with the 'little tube' when using a blind filter. Next to nothing comes out there.

With regards to the pressure screw - I am positive that I screwed into the right direction. It was indeed clockwise to increase the pressure. In fact I wrote a small user-manual on this procedure - see (in Dutch - but with photos): http://www.koffiepraat.nl/forum/viewtop ... =12&t=5833

Any other ideas?

#6: Post by **DaveC** » August 5th, 2014, 5:04 pm

sinterklaasje wrote:With regards to the pressure screw - I am positive that I screwed into the right direction. It was indeed clockwise to increase the pressure. In fact I wrote a small user-manual on this procedure - see (in Dutch - but with photos): http://www.koffiepraat.nl/forum/viewtop ... =12&t=5833
Any other ideas?

If when using a blind filter it seems to vent quite violently and normally as if it under 9 bar pressure or more...it's possible the gauge could be defective......

if it vents quite gently and anaemically, then it could be the pump, or a blockage in the inlet tube, piece of teflon tape etc.. Does the pump make any unusual noises?

August 6th, 2014, 2:53 am

Ok - tried that and strangely enough (I guess I didn't pay attention to it so far).... the release when using the blindfilter is almost negligible, dispite engaging the machine for roughly 20 seconds.... that must mean no water is being fed to the grouphead, no? I don't hear any strange noise from the pump though - at least not something that immediately strikes me as odd.

Again a small video of what is looks/sounds like:

#8: Post by **hrbrun** » August 6th, 2014, 6:08 am

If you remove the PF and flush water thruogh the grouphead, what happens?

The shop where you bought the machine should set you in contact with Izzo support, or at least ask Izzo how you can determine if pump or something else is broken on your 2 months old machine.

August 6th, 2014, 8:22 am

Not much to be honest.... I had the store's Technical department on the line earlier today and they advised me that there might be an 'air bubble' in the piping - so it's unable to build up pressure. I had to flush the machine by taking hot water (right hand side of machine)... this seemed to resolve the problem (=pump pressure back to normal levels)... however the machine only maintained this for 1 espresso... after that - back to the same problem. I'll return the machine tomorrow for investigation and repairs......

August 6th, 2014, 10:40 am

I actually think it points to 3 possible problems now some I mentioned earlier. You've confirmed in the earlier posts that the 2 bar or so shown on the Gauge is accurate.

1. restriction on the inlet - kinked pipe, large inline softening filter on pipe (remove), blocked pipe

2. faulty or jammed autofill solenoid (however i would expect the steam boiler to eventually overfill and water to come out of safety valve or vacuum breaker (if steam boiler off)...so possibly unlikely

3. faulty pump - unusual and probably unlikely as you did manage it to get full pressure, even if it was for 1 shot, it would make a faulty pump unlikely.

Sometimes priming can be a problem against a hot machine, so take off any inline filters and just try against a cold machine, also remove top and check hose for kinks.