Hello,

I have an Izzo Alex Duetto II for about 12 years now. I changed the group head kit about 2 years ago and descale every 6 months. I am quite a hands on person mechanically but need some very good guidance on electrical items (apart of unscrewing wires and or soldering them - the mechanical part!). Other than that the machine always worked flawlessly.

This week I am noting that the brew water is quite cold about to 25-30 degC after a shot of espresso felt cold and blunt. I poured some water from the group and easily dipped my finger and then the thermometer read about 30 degC. The PID is set and shows 96deg C (even though some parts of digits have failed but I can read it). The steam boiler function is normal with correct temperature of water both out of steam wand, tap water and PID display of 123 deg C.

I am attaching a video clip of the machine at start up…hope someone has about 5 minutes to watch it and maybe help me out with some diagnosing. The F.02 is set at 5 and this machine is 230V.

Switch on

I would appreciate any diagnosing and assistance with this issue.

Regards to all.

The system appear to initially be heating normally, but then abnormal readings after that and the brew boiler heating light doesn’t come on. So I suspect the boiler is cooling down when you make your espresso. The cold water entering after that simply cools it down even further. I suspect the error reading is in the 100s and not 7 or 10 etc…

You can check this by simply switching the sensor wiring (brew to steam boiler and steam to brew boiler)…turn down the “steam temp” (which of course will now be the brew boiler) to 93C and raise the brew temp to above 100… then see if it works normally after that and the problem transfers to the steam boiler.

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Thanks DavecUK to reply. I am just back from work and switched on the machine again. Once more the t1 is 106 on the PID but getting water from the group at 45degC. The t2 is showing 126 on the PID and from the tap I am getting water at 80deg C. I am not sure to understand your sentence: I suspect the error reading is in the 100s and not 7 or 10 etc…Can you please explain this if possible.

Now to switch the sensor, I have to pull the plastic pieces that slide in each other correct? However, when I switch the machine on it will start to heat the water, so how would I setup the temperatures before any heating actually starts pls? I definitely do not want to do something that would damage the machine even more…so usually I try to be sure I am understanding 100% the steps that I have to do when it comes to things like this. The swapping has to be done as per below edited image correct? If I do not manage to adjust the temperatures is there any damage that can be done to the brew boiler as then its water will go to 126deg right?

I thank you again for your time and hope to manage this and report back…some time tomorrow now to ensure the machine is totally cooled off.

Can I ask if you are a technician yourself on Izzo machines please?

    emann Can I ask if you are a technician yourself on Izzo machines please?

    I did the top level design for the machine almost 18 years ago. I still have machine number 0001

    emann However, when I switch the machine on it will start to heat the water, so how would I setup the temperatures before any heating actually starts pls? I definitely do not want to do something that would damage the machine

    Well you will have 3 or 4 minutes to make the adjustment as the water won’t heat instantly…just turn down the “steam” setting on the PID to 93, and either leave the “brew” setting on the PID as it is…as you’re not worried about steaming, just fault identification.

    You won’t damage the brew boiler even if you muck it up…as the limit stat is set to 135C (from memory) and it will simply cut the power to the brew boiler. But iof the brew boiler gets to 126C, you will get loads of steam from the group. 😁

    Don’t over think it, just swap the probe connections over and lower the steam temp to 93…then see what happens.

    On a more serious note, check your pump isn’t leaking water into the motor when you get time!!

    It was one design decision I made that Izzo didn’t implement (it was in my original design docs to cage the motor pump unit and have the pump at the bottom)…until years later when they found I was right.. Below is an article I wrote 15 -17 years ago.

    http://coffeetime.wikidot.com/duetto-pump-checks-and-home-made-leake-detector

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        Hi DavecUK - its really great to be talking with you here then in view of being the designer of model 0001..is your machine still up and running then?

        Ok..so after work I took the courage and went for it. Marked the wires to ensure no mix up and switched the probes. I turned machine on and changed t1 to 126 and t2 to 96. Below is a link recording the process of heating up. I noted that t2 on the PID was maybe raising a bit erratic?? and given some failed digits was not sure of the rate or how the temperature was raising. I also noted that the lights indicating heating remained on up to a point where I said I stop the heating as the steam pressure reached the red zone on the gauge and approaching the upper limit.

        Swapped Probes

        The below is another link for a video showing the water coming out of the group…I reckon much hotter even than 96 as it was also steaming.

        water from group

        So not sure what to deduct from this. Firstly temperatures on PID raised with both setups of the probes. Secondly it seemed that heating was not going to stop and this is different to unswapped probes as at reaching 96 and 126 the lamps switch off. Water from tap and steam wand indicated a temp of 50-55deg C - so very low from the unswapped probes. Water from the group was above 80 - so contrary to the unswapped probes this water heated up well. This all up to the point where I then stopped heating by pressing both PID buttons. I then switched the machine off and drew out some water to reduce pressure. Machine is now left to cool.

        I look forward for your assistance now pls.

        BTW - great point you make on the pump and motor - from which version onwards did Izzo take on your suggestion on the design then?

          emann Hi DavecUK - its really great to be talking with you here then in view of being the designer of model 0001..is your machine still up and running then?

          Last time I used it yes…still looks brand new.

          emann BTW - great point you make on the pump and motor - from which version onwards did Izzo take on your suggestion on the design then?

          Version 4 I think….way too late.

          back to your problem, I hope you are being precise and did what I asked, otherwise this will; get expensive for you, as the advice I give will be based on faulty information. Answer each question precisely. Remember when you swapped the probe wires round this also swapped the steam and brew temps around on the PID

          1. When you swapped the probe wires and steam temp became brew temp and vice versa, did you also change the temp settings appropriately?
          2. It seems like the steam boiler just continued heating without the heating element going off, is that correct and considering the only thing that changed was the probe wires for the steam boiler now connect to the brew temp part of the PID. What did you change the brew temp to on the PID? as it’s now controlling the steam boiler
          3. Did you definitely change the steam temp (which is now brew temp) on the PID to a sensible brew temperature like 93?

          emann Secondly it seemed that heating was not going to stop and this is different to unswapped probes as at reaching 96 and 126 the lamps switch off. Water from tap and steam wand indicated a temp of 50-55deg C - so very low from the unswapped probes. Water from the group was above 80 - so contrary to the unswapped probes this water heated up well.

          The potential problems:

          1. The Brew temp part of the PID is never turning off the SSR that controls the heating element, so the problem transferred to the brew boiler and you switched it off before the resettable limit stat tripped. So before the swap the brew boiler was over heating and tripping is much lower rated 135C limit stat. However, these are no self resettable and you don’t mention resetting a limit stat ever. So it’s not this
          2. You did something incorrectly for the testing, or are getting mixed up. High probability
          3. Brew boiler limit stat is faulty and tripping early, but for 1 above it can’t be this and it didn’t trip when the brew boiler temp got very high. So it’s not this
          4. Intermittently faulty PID, but the fault did not transfer to the steam boiler, you had better hope it’s not this, but I don’t see how it can be

          emann Water from tap and steam wand indicated a temp of 50-55deg C - so very low from the unswapped probes. Water from the group was above 80 -

          I absolutely don’t understand this

          1. You can’t get water from a boiler below 100C, there is no steam pressure to push it out
          2. Was this before you swapped probes, if so it’s just confusing me

          emann Thanks DavecUK to reply. I am just back from work and switched on the machine again. Once more the t1 is 106 on the PID but getting water from the group at 45degC. The t2 is showing 126 on the PID and from the tap I am getting water at 80deg

          Did you swap the temperatures over, was this after you swapped the probe wires????

          emann Marked the wires to ensure no mix up and switched the probes.

          Be very very precise about what you are doing. All you should be doing is swapping the probe wires (not the probes), is this correct.

          I say all this because the results you are getting just from swapping the probe wires are super confusing

          1. The over heating of the brew boiler means you didn’t change the temps over as I asked or did you?
          2. The over heating of the steam boiler is confusing, seems the PID didn’t ever want to turn it off, but that’s the opposite of what’s happening with the brew boiler (so it doesn’t make sense…only the probe wires have been swapped?

          I expected the steam boiler to either heat normally, or experience the same problem as the brew boiler, and the brew boiler to work normally…but this isn’t happening???

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                        DavecUK

                        before answering the questions dave I want to be sure I interpreted your proposal to swap probes at the sliders and not at the PID. What I mean is this.

                        This is the original setup of the probes (PLS NOTE RED SLIDER RIGHT AND WHITE SLIDER LEFT from front of izzo):

                        The below is the swapped setup of the probes (WHITE SLIDER RIGHT AND RIGHT SLIDER LEFT):

                        So like this I place the probe of the brew boiler attached to the red slider and the probe of the steam boiler to the white slider. At the PID I set t1 to 126 and t2 to 96 just after I switched on the machine. Original readings up to last time I tested on the machin yesterday t1 was set to 96 and t2 to 126.

                        Connections on the PID (i.e. the other end of the wires of the probes which connect into the PID I did not touch anything)

                        Can you please confirm this was your instruction or possible I understood you wrong please?

                            emann This was what I wanted you to do with the probe wires and temperatures, although 93 for the brew boiler (now t2)

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                              Noted so then I followed correctly and the t2 was set to 96 and not 93.

                              to be sure I am passing the correct information i switched on the machine now after it cooled off since the swap to check again the temperatures I set them to….please note below:


                              and t2:


                              However now the machine is showing me this and the steam boiler light is not switching on:

                              I think this is A3 in view of the parts of the display not working.

                              Any indication how best to proceed please?

                              Yeah, these are the error codes for that particular PID used on the MK2. Just remember with the probe wires crossed over, A3 is really referring to the “coffee boiler”…so one could assume it might be a faulty limit stat or coffee boiler temp sensor?

                              Right click image and open it in a clean tab and you will see it full size.

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                              Hi and goodmorning…thanks once more to get back to me.

                              So in going forward, I am trying to be logical and understand what happened. I think at this stage and in consideration of the age of the machine it is appropriate to get some parts replaced in the hope of getting it alive again. Please consider the below:

                              1. Initial problem was coffee boiler water not being heated as noted last weekend.

                              2. As per advise (I now understand I followed correctly what you proposed), I swapped the wires of the coffee and steam boilers by exchanging the red and white sliders. The temperatures were set as t1 to 126 and t2 to 96.

                              3. It was expected that the steam boiler would return cold water and the coffee boiler would return heated water. This did not happen as explained in my thread above. What happened was that it seems that both boilers continued to be heated even when the PID was indicating they reached the set temperatures. As the steam boiler continued being heated and pressure went into red zone, I then switched off the machine. Water coming out of coffee boiler was steaming as per video.

                              4. On switching on machine after it had cooled, I got A3 error - from table it is related to steam boiler which with the probes swapped this now refers to coffee boiler which returned steaming water on test above.

                              5. In this case I am thinking that it is best to proceed with some overhauling of the machine in view of its age and that it was never serviced (always worked great!) and get a some new parts including:

                                a. PID

                                b. two temperature probes

                                c. two SSRs

                              6. What do the SSR actually control please? and are these triggered from the PID?

                              7. What do you think of this logic please?

                              8. Also, would you have a parts list and service manual of this machine if possible to share with me as I cannot find this anywhere online.

                              I look forward for your thoughts and once again thank you in advance.

                                emann In this case I am thinking that it is best to proceed with some overhauling of the machine in view of its age and that it was never serviced (always worked great!) and get a some new parts including:

                                a. PID

                                b. two temperature probes

                                c. two SSRs

                                What do the SSR actually control please? and are these triggered from the PID?

                                What do you think of this logic please?

                                Also, would you have a parts list and service manual of this machine if possible to share with me as I cannot find this anywhere online.

                                I would avoid just buying masses of things you may not need and it’s expensive too.

                                a. PID might be faulty, but not sure yet

                                b. only one may be faulty, or may not be!

                                c. the chance 2 SSRs have failed simultaneously is almost zero. (plus they tend to fail closed)…but usually the problem would stay with the SSR, which in this case it doesn’t appear to have done? As however you swap the probe wires, the same SSR is always controlling the same boiler, but in response to a different probe.

                                I think you need to do some more diagnostics…… as it could even be something as simple (and cheap) as a faulty brew boiler limit stat (although it’s not this because when you swapped the probes, the problem didn’t conntinue to happen with the brew boiler.

                                Perhaps start with a brew boiler temperature probe.

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                                  ok and thanks to reply.

                                  • the temperature probes are the same for both brew and steam boilers please correct - like the one below for my izzo?

                                  Probe

                                  • Would you happen to know any suppliers for Izzo parts in europe please? The bella barista is the most expensive unfortunately and I would need to add tax when it arrives in Malta. The link above has a shipping cost of Euro28 whatever you buy..maybe I can check with some other online shops please.

                                  Thankyou.

                                    5 days later

                                    hi - as an update I ordered the two probes now.

                                    Until these arrive, is there any product I can use on the inside of the machine over the pipes and fittings to clean them up and restore some shine on them?!

                                      7 days later

                                      hello…some hurray and then some other disappointment!

                                      So the technician advised that the probes were changed and I picked up the machine on wednesday. On initial start I could note some thing not normal (more on this below), however in as far as the PID switching on heat elements and cutting off when temperature was reached in the boilers and drawing of water at the correct temperature from the group goes, machine was working perfectly. This was on the shots used for wed and thursday.

                                      I could initially however note that on first start, the pump did not kick in to take water from the reservoir. However since it was functioning normally with the lever I thought that the boilers were full after the repair was completed and did not need water. In all the time the machine was on, I could not hear the pump starting on its own to take water from the reservoir. I also noted that the steam pressure was above the 1.5bar and was getting quite strong flow of steam, almost saying that it is not normal that I am getting such an amount of steam when I purge the wand. I lowered the steam temperature and got to 122deg and got pressure to the factory level of 1.2 - the same reading for all these past years. Pressure gauge of brew seemed to be working normally and also water from brew coming out hot. I could note that when I move the lever, whilst water is coming out of the group, the pump seemed to be taking water as well from the reservoir.

                                      On the second start up of the evening, operation remained similar to the above - basically powerful steam (like wet steam with a lot of water) and no water taken from the reservoir.

                                      This morning, operation was also normal up to reaching temperatures. Steam was the same - powerful and wet. BUT, on moving lever, I can hear the pump like humming but no water is coming from the group now.

                                      So basically I am back to diagnosing and repairing again however with at least two new probes in both boilers that are working fine!

                                      Any thing I can do myself before going back to the bench again?

                                      Thanks.

                                        emann Any thing I can do myself before going back to the bench again?

                                        From what you have said, the autofill solenoid either:

                                        • is being held permanently open (powered all the time)
                                        • faulty
                                        • blocked

                                        But a few questions..to help clarify which one it might be

                                        • When you say no water from group, do you actually mean nothing
                                        • When the pump is running is water being drawn from the reservoir
                                        • Was the steam boiler up to temperature or cold
                                        • Was it descaled

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                                          Hi Dave - answers below in order:

                                          • without portafilter, water was trickling from group. With portafilter loaded with coffee and in group, no water coming out and pressure gauge of group remained zero
                                          • when the pump is running (lever on to make coffee) I could note water being drawn from the reservoir, but at no point in time did I hear the auto-fill being activated. Now I only hear a hum when I operate the brew lever.
                                          • steam boiler up to temperature and steady for about 20 minutes at 122deg.
                                          • I do descaling ¾ times a year depending on use. Last descaling done was end december 2023…usually my next descaling would be end march to end april depending on use.