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  • Breville BES920 - Not reaching temperature

    Hi, I'm having some trouble with my Breville BES920. It works perfectly fine from a cold start. However whenever my machine has been used recently, when I go to use it again it won't heat past 63-73°C.The machine will only reach full temperature if the machine has been switched on from a cold start. This is fine for my morning coffee but troublesome when my wife tries to make hers half an hour later. Any ideas as to what might be causing this issue? The steam works perfectly fine, but the main boiler won't reach temperature.

  • #2
    Hi Warpedbread

    Have you checked the error logs? This will be a good starting point to narrow this fault Also, how often do you descale your BES920?

    To access your BES920XL Error/Fault Log:
    1. Using the Control Panel, shut the machine off;
    2. Hold the single and double shot/cup buttons together (at the same time) for 5 seconds and then turn your BES920 on again;
    3. When the Service Menu appears, press "menu button" and this will display your BES920's shot counter (divided by 10)
    4. Then you can press the menu key again and that will let you view/scroll through the error codes in ascending order from 00 to 12

    Here's what the various error codes mean on the BES900 and BES920 models (NOTE: these are Fault Codes (00-12), and not err codes, and if your LCD says "err3", for example, this is not "03 ... Coffee Boiler NTC" but is an error under "Fault Code" "04 ... Grouphead NTC Sensor" error):
    00 ... Steam Boiler NTC Sensor Error
    01 ... Steam Boiler NTC Sensor Error
    02 ... Coffee Boiler NTC Sensor Error
    03 ... Coffee Boiler NTC Sensor Error
    04 ... Grouphead NTC Sensor Error
    05 ... Grouphead NTC Sensor Error
    06 ... No Water In Steam Boiler
    07 ... Water over-flow condition in Steam Boiler
    08 ... Coffee Water Flow Failure
    09 ... No water in Coffee Boiler detected at Boot Up
    10 ... Coffee NTC Sensor Over Temperature
    11 ... Steam NTC Sensor Over Temperature
    12 ... Grouphead NTC Sensor Over Temperature


    Mark down the ones that show anything other than a 00 after the first two digits and colon. So for example, if you have "03:51" displayed when scrolling through the error/fault log, record that number, and report back here what you find for further consideration If you check out this video, at about 1 minute 24 seconds it will show how to access the "Service Menu". NOTE: Consider NOT clearing your error codes . . . they contain important diagnostic information.

    There is also a "Self-check mode" method to check the temperature being registered at various being recored at your BES920's Grouphead NTC sensor, Steam Boiler NTC sensor and Coffee Boiler NTC sensor. To enter that Self-check mode visit the same video and at about 3 minutes 32 seconds it will show you how to access that mode.

    Comment


    • #3
      Originally posted by WWWifi View Post
      Here's what the various error codes mean on the BES900 and BES920 models (NOTE: these are Fault Codes (00-12), and not err codes, and if your LCD says "err3", for example, this is not "03 ... Coffee Boiler NTC" but is an error under "Fault Code" "04 ... Grouphead NTC Sensor" error):
      00 ... Steam Boiler NTC Sensor Error
      01 ... Steam Boiler NTC Sensor Error
      02 ... Coffee Boiler NTC Sensor Error
      03 ... Coffee Boiler NTC Sensor Error
      04 ... Grouphead NTC Sensor Error
      05 ... Grouphead NTC Sensor Error
      06 ... No Water In Steam Boiler
      07 ... Water over-flow condition in Steam Boiler
      08 ... Coffee Water Flow Failure
      09 ... No water in Coffee Boiler detected at Boot Up
      10 ... Coffee NTC Sensor Over Temperature
      11 ... Steam NTC Sensor Over Temperature
      12 ... Grouphead NTC Sensor Over Temperature
      Is there another list of Err codes or are Err codes the fault codes +1?

      There is also a "Self-check mode" method to check the temperature being registered at various being recored at your BES920's Grouphead NTC sensor, Steam Boiler NTC sensor and Coffee Boiler NTC sensor. To enter that Self-check mode visit the same video and at about 3 minutes 32 seconds it will show you how to access that mode.
      This is excellent, want aware this information was publically available before.

      Comment


      • #4
        As per the title, but I'm still not sure what's wrong thus another topic on this.

        Brew temp doesn't get to temp. Ive had the odd power trip but could never be sure what caused it. Either heating element or pump as it usually occurred on start up but not until it was up to temp and I primed the brew system by running the hot water outlet. But all was well apart from the odd trip of the circuit breaker that was quite rare.

        All of sudden though the brew temp hasn't reached temp. It had no problems at all until this morning. At first it seems if I ran the hot water outlet it brought the temp up a little.. But never anywhere near 93 degrees. Even then the hot water outlet didn't seem anywhere near temp.. But it flows water just fine.

        Steam boiler is perfectly fine.

        When I drain the brew boiler at the descale screw it doesn't seem to drain any water..

        No error codes in the service menu since I last reset it a while ago.

        So I'm thinking it's either the water level sensor in the brew head boiler or the pump...

        Assuming this is a different pump to fill the brew boiler?

        Or is it the same one that pumps the hot water out so pump is fine?

        I will try to check if I can fill the brew boiler up manually but I struggled to pour much in the outlet where the hoses go into the brew boiler. I couldn't remove the temp sensors and was worried I might break them. Clips out and they rotate, but they didn't want to come out.

        So you can see I've read a little. I've thought a little. But still not certain.
        Last edited by PeteRepeat; 25 March 2022, 10:00 PM.

        Comment


        • #5
          I had this in my own topic but it got moved here by admin (post above) I guess because it's very similar (I had read this topic before posting).

          Mine never gets to temperature though, not even from a cold start so subtly different.

          Comment


          • #6
            I have noticed that on occasion, say after stopping the hit water outlet, that steam comes from the input connection into the steam boiler. Sometimes it's from the other outlet that goes from the steam boiler to the brew boiler. Not a lot of steam, but some leakage that I'm sure isn't meant to happen. Perhaps unrelated..

            Comment


            • #7
              Ok so it seems there's water coming through the white line from the steam boiler to the brew head boiler so no blockages there. Then if I disconnect the other one then the water doesn't come out the hot water.. So I guess the pump puts the water through the steam boiler to the brew head boiler, through to the hot water outlet..

              If I open the drain when I turn the hot water outlet on water comes out the drain.. But the boiler doesn't seem to be filling seeing no water drains out unless the hot water outlet is on.

              Still haven't worked out how the system works fully. How can water be entering the brew boiler so it goes out the hot water outlet, but it not drain any water when I open the drain screw which indicates no water to me.
              Last edited by PeteRepeat; 26 March 2022, 08:15 AM.

              Comment


              • #8
                Right.. So I decided to pull the group head collar out and replace it as I have the 1st gen 920 with the old single collar you can no longer buy and I had a spare complete group head with the newer 920 design sitting there waiting to go in. Replaced that and through the process of that I decided to check the thermal fuse for the brew head and it was shorted. So I changed it over with the old group head fuse (same amp rating, slightly lower thermal cut out so figured it was conservative and would only blow at lower temps but should be ok..

                So now I see the temp rising. Must have been not putting water in the boiler or something because the heat er element wasnt working?

                However I now have thermal runaway. Went over 105 degrees nowand hadn't stopped. I've checked the resistance on the heater in the brew head and it's 77 ohms which seems about right? Perhaps I now have a problem with the pid or do they need to relesrn the pid parameters? Seems the heater element keeps heating when it reaches temp as it measures 125V across the terminals still.. Hopefully just moisture on the board as I have read elsewhere (plus I emptied boilers etc so had a lot of steam come up) however not sure how long I need to wait...
                Last edited by PeteRepeat; 26 March 2022, 12:43 PM.

                Comment


                • #9
                  I'm about 99.9% certain your problem is the leaking steam (from the O ring on the steam boiler) shorting the triacs on the underside of the cup warming tray, causing the heating element in the brew boiler to not switch off, which caused the thermal fuse to blow (which protected the heating element as designed). If you leave the machine unplugged and open for 24-48 hours to dry out the triacs, about 80-90% of the time they come good. If not you need to have the triac board replaced (around $70 part from memory). You'll also need to replace all leaking O rings before turning it on again, obviously.

                  The reason the brew boiler doesn't drain sometimes when you open the drain is due to an air lock.

                  The reason the brew boiler had some temperature and got more temperature when you ran the hot water tap, is the path of the water from the pump to the brew boiler runs through the steam boiler. When everything is warmed up the water entering the brew boiler will be approx. 88°C.

                  Comment


                  • #10
                    Thanks. Makes sense. I only ever saw the under temp but as you said, triac board stopped functioning properly due to steam leakage and the brew boiler thermo overheated and tripped the thermal fuse...

                    Is it possible that the rare electrical trip could have been because of the blowout of steam past an the oring on the steam boiler.. Or perhaps I have another issue as well like the boiler element.. Which meters ok but I guess that doesn't guarantee its not temperamental.

                    If the bes980 wasn't so much, and even more so the bes990 I may have retired this machine as 6k+ shots is pretty good I feel. ​​​​However while I keep looking at a new machine I keep coming back to fixing this one.. Have replaced the solenoid twice (fairly cheap) and replaced the group head just now due to broken collar. That's about it. Well overdue for an oring change...


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                    Comment


                    • #11
                      Yeah the steam can cause an earth trip

                      Comment


                      • #12
                        Originally posted by PeteRepeat View Post
                        As per the title, but I'm still not sure what's wrong thus another topic on this.

                        Brew temp doesn't get to temp. Ive had the odd power trip but could never be sure what caused it.
                        . . .
                        Hi PeteRepeat

                        "power trips" can be caused by faulty components in an appliance (or in the case of a BES920XL impressive level of design and manufacturing, a "machine"). This can be caused by an open or shorted circuit in a component, such as an NTC (Negative Temperature Coefficient) Sensor, creating an excessive demand for voltage/current thus tripping a breaker. This breaker tripping is a good thing, not only because it protects the wood your home is constructed from, but also your valuable Espresso machines components, such as heating elements and brain box etc. The symptoms you describe appear to be related to temperature monitoring regulation.

                        There are several NTC sensors on your BES920XL PeteRepeat These are designed not only to help regulate temperatures within your boilers and Grouphead heating element etc. but also to protect your machine in case of over-heating, corrosion, or other failure.



                        Add to this that the Breville Dual Boilers (BES900/920 series etc.) utilize two PIDs (Proportional-Integral-Derivative controller), one of which is on the Brew Grouphead and the other PID on the Brew Boiler (the smaller of the two Boilers above the Grouphead), and you have a complex mix of magic and sorcery to deal with.
                        1. If your NTC Sensor on your Grouphead is shorting (if it was open the machine just would not reach "ready" state), then you'll be getting over-voltages and possible "power trips" (as you describe your breaker tripping, particularly if you have GFCI, Ground Fault Circuit Interrupter, protector type breaker).
                        2. If your NTC Sensor on your Brew Boiler is shorting (again, if it was completely failed and "open" the machine would not heat at all), then you may also potentially experience "power trips" as your machine cause and over-voltage spike as it attempts to draw more and more current from the electrical circuit.
                        As you are experiencing a "power trip" and depending on what temperature your 93℃ unreached target is relating to (the Grouphead temperature or the Brew Boiler temperature), you may have a situation where the PID cannot carry out its algorithm to reach set point properly . . . particularly if you have a failing or shorting NTC Sensor that is not providing consistent or stable data to the PID program. Noise on a thermal component (as in a shorting NTC Sensor) in particular can result in the output bouncing around and this interferes with achieving set point and loop performace in the PID.

                        NTC Sensors have a lifespan. Over time their ability to accurately monitor temperatures can drift or become incapacitated. Operational one minute, they can be a hot-mess the next minute. NTC Sensors are brilliant for their incredible precision within the ranges required by Espresso Machines. However, when they begin to fail, due to long term heat exposure or other factors such as corrosion etc., they can begin to give errant readings.

                        You'll need to check your NTC/Thermal Sensors, and one or more may need replacing. While its true that temperature stability is regulated via a "heat-exchange" loop between the Steam Boiler and the Brew Boiler, this shouldn't cause your breaker to trip (a "power trip") as its a passive system component with no electrical connections.

                        Which component is giving you the ". . . never anywhere near 93℃" reading? Is that your Grouphead temp or your Brew Boiler temp? I assume because you are targeting 93℃ you are referring to your Brew Boiler but the Grouphead temperature is also monitored.
                        Last edited by WWWifi; 26 March 2022, 08:33 PM.

                        Comment


                        • Allen
                          Allen commented
                          Editing a comment
                          Might I have a similar problem? I have a Breville Dual boiler BES920 purchased almost exactly 3 years ago. Made a coffee this morning and switched it off. Switched it on again at lunchtime when it immediately showed a temperature of 111 ºC . I realised the unit was VERY hot, so switched it off at the mains and let it cool down. Some hours later I plugged it in, switched it on using he power button and it showed 42 ºC. Switched it off but left it plugged in, and on switching it on again a few minutes later found the temp had risen to 55 ºC . Something astray with its entrails. Assume it's a job for the repair shop?

                      • #13
                        Here's a few pictures of the BES900XL and BES920XL Grouphead NTC Sensor and Brew Boiler NTC Sensor locations . . .
                        Breville BES900XL BES920XL Grouphead NTC Sensor Location Click image for larger version  Name:	Screen Shot 2022-03-26 at 2.48.46 AM.png Views:	0 Size:	1.31 MB ID:	907045To answer level3ninja's question about the oddity of the Error Fault Codes and "err" codes not corresponding, I'm not sure why Breville has this unusual discrepancy except that some "err" codes might correspond to more than one "Fault" condition . . . here's an example of the err3/Fault code 4 listing:
                        Breville Dual Boiler Fault ver err code discrepency
                        Attached Files

                        Comment


                        • level3ninja
                          level3ninja commented
                          Editing a comment
                          What are all the possible reasons for Err3?

                        • WWWifi
                          WWWifi commented
                          Editing a comment
                          There are two possible Fault Codes for Err3. Fault 04 and Fault 05. Fault Code 04 is for an "Open" or disconnected circuit (as can be seen above in the picture) in the Grouphead NTC Sensor. Fault Code 05 is for a "Shorted" circuit, which can cause breaker tripping, and still function, giving inconsistent or intermittent readings, until it fails completely, likely entering the "Open" state where current no longer has a path through the NTC sensor at all.

                          NTC Sensors are created commonly by combining ceramic and rare earth metal mixtures and are often encased in a material of some sort, a heat resistant polymer or glass even, to protect them from the elements. They are well esteemed for their superior precision and accuracy in monitoring and regulating temperatures within a specific range. Over time, these NTC protective jackets/coatings can be damaged by heat or water/steam erosion of just corrosion of other kinds (of which there are several). I'll attach a picture of a particularly nasty Grouphead corrosion issue that ended up destroying the NTC sensor and generating an Err3 fault (which may mistake for Fault 03, Coffee Boiler NTC short, which it is not).

                      • #14
                        I have ordered a new triac board and some boiler orings. This machine is refusing to die just yet... Just can't justify the money for a bes980 or what I was even more tempted with the bes990 until this thing has a major component go...

                        Comment


                        • #15
                          Originally posted by WWWifi View Post

                          Which component is giving you the ". . . never anywhere near 93℃" reading? Is that your Grouphead temp or your Brew Boiler temp?
                          After fixing the thermal fuse on the boiler, it's now only over temp on the boiler. All other temps (group head and steam boiler) checked in diagnostics are ok.. The bubbling I hear and the obvious positive pressure indicated by the leaking orings seem to indicate boiling occurs approaching 100 degrees 😲

                          So who knows maybe I could have replaced triac only (??) but decided a board was only like $40 so less risk.

                          hopefully all ntc sensors are fine... couldn't remove them from the boiler without brute force.

                          Thanks for all your info. very informative..

                          ​​​​​

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