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  • EM6910 No steam just spurting out cold water

    Hi fellow snobs
    so I'm thinking its the heating element?

    the pump must be pumping its just not producing steam? Its out of warranty but rather than send away I would like to grab the parts and repair myself

    any ideas appreciated also parts online store link

    cheers Terry

  • #2
    Hi Terry
    Welcome to the forum.
    From the limited details you have provided I would guess that it is more likely to be a faulty thermistor on the steam thermoblock.
    I would suggest some careful measurements with a multi-meter would give a better indication of where the fault is but please make sure that the machine is unplugged from the power first.
    The resistance of the thermistor should be about 100k when cold and it should decrease as it gets warmer.
    A faulty heating element usually prevents the machine from getting past the initial flashing green 'power' light stage so the steam pump will not work until all of the ready lights come on.

    This section has lots of posts opening up the machine and fault finding but please ask if you need more help.

    Trev

    Comment


    • #3
      thanks for your reply Trev

      limited? Sorry not sure what more to add, the main head gets hot and the hot water wand work, just that I can run room temp water spurting in pulses through the steamer forever and it doesn't get any warmer...or steamier
      Sunbeam sent me an instruction saying it may be a common air lock but that remedy didn't fix it unfortunately

      Comment


      • #4
        Hi Terrry
        Sorry if it sounded like I was being difficult in asking for more detail but when trying to remotely diagnose faults with these machines every little bit of info helps. Things like if the fault is intermittent or permanent, what the indicator lights are doing, whether the water coming out is stone cold or slightly warm and if the problem came on suddenly or slowly got worse can all help in the diagnosis, especially when there is a micro-controller in the mix calling the shots.
        Also, not knowing how confident you are in working on electrical/electronic devices makes it difficult to know what level to pitch a reply to - I'd hate to suggest to someone with little experience that they go poking around inside the covers and risk making things worse or seriously injuring themselves - hence the request for more info.

        As for spare parts, some are available online or from sponsors, but other than that I don't have any other suggestions. Once you know exactly what you need I'm sure others on here will have some recommendations.

        So, I still reckon the NTC thermistor would be a good place to start as these are fairly easy to check and cheap to buy. After that the list of possibilities would include the control board, thermal fuse, thermal cutout, heating element and relay contacts, although these usually just stop it from getting past the initial warm-up stage.



        Regards
        Trev

        Comment


        • #5
          Originally posted by Xanthine View Post
          Hi Terrry
          Sorry if it sounded like I was being difficult in asking for more detail but when trying to remotely diagnose faults with these machines every little bit of info helps. Things like if the fault is intermittent or permanent, what the indicator lights are doing, whether the water coming out is stone cold or slightly warm and if the problem came on suddenly or slowly got worse can all help in the diagnosis, especially when there is a micro-controller in the mix calling the shots.
          Also, not knowing how confident you are in working on electrical/electronic devices makes it difficult to know what level to pitch a reply to
          All excellent points, i didn't think you were being difficult, sorry for my vagueness

          this fault seems permanent
          indicator lights are all illuminated, not sure what they are supposed to do when steaming? when boiler water is activated all but the power light goes out
          water is warm - its like milking a cows teat
          problem came on suddenly

          well i'm handy but not into electronics, I have a plumbing background not electrical, I would be more inclined to start replacing components

          Comment


          • #6
            Luke-warm water from the steam nozzle further indicates a thermistor fault which is a fairly cheap and simple fix. It is clamped to the steam thermoblock one end and the leads plug into the control board the other, but it needs a smear of heatsink grease when replacing and the control board has to be lifted out to get to the plug. This board has many exposed points which operate at mains potential so it is absolutely essential to make sure the mains plug is disconnected before opening the machine and I would be hesitant to recommend attempting it. If the rest of the machine is in good condition it may be worth having it done by a service centre as it should not be too expensive (unless the fault is in the control board).

            By way of explanation, when the machine is first turned on the heating elements in both themoblocks are switched on by their relays and begin heating up. The thermistors sense their respective temperatures and tell the control board to pulse the relays off and on until they come up to temperature - around 90deg for the brew water and 120deg for the steam.( If the steam thermistor is faulty and has gone low resistance it thinks the thermoblock is already hot and does not turn on its heating element). This is the clicking which can be heard during warm-up. Once their temperatures stabilise the other display lights come on and the machine is ready. If hot water or steam is required the respective thermoblock heating element is turned full on - hence a faulty thermistor will produce warm water).

            Trev

            Comment


            • #7
              Hi Trev

              thanks for your detailed reply, its much appreciated
              i contacted spare big warehouse for a price for the SUNBEAM EM6910 PN 1648689 (310) steam thermistor but having trouble with their website just showing me blank pages on 2 different PCs
              can anyone recommend another supplier please?

              scratch that, got in another way and have ordered the part....

              Comment


              • #8
                Hi Terry
                OK on getting the replacement thermistor but just a couple of comments before you go ahead -

                First, I just re-read your previous post where you said
                when boiler water is activated all but the power light goes out
                . and this has me wondering if the fault is control board related rather than thermistor. From memory, in a normally operating machine the display lights don't change when steaming. It might pay to measure the thermistor resistance with a multi-meter set to ohms range first before going to the trouble of removing it. This would require removing the two mounting screws at the bottom of the board and it should be possible to lift it out to one side with all wires attached, enough to unplug the thermistor lead and measure it. It should read about 100k ohms at room temp.

                Secondly, if you do swap out the thermistor, make sure you re-run the leads of the new one exactly as they were originally so they are not likely to be shorted out by hot or vibrating parts in the machine. Its important to keep all wiring secured, as it was originally. If necessary take photos first. And don't forget the thermal grease between the thermistor & boiler.

                And, once again I would stress the importance of working safely with mains power. Always double (and triple!) check that the mains cord is unplugged before opening the machine and don't plug it back in again before all of the covers are back on. I would still recommend having the job done by a professional if you have any doubts.

                Trev

                Comment


                • #9
                  Originally posted by Xanthine View Post
                  . and this has me wondering if the fault is control board related rather than thermistor.
                  Bugger, really? Can anyone confirm whether or not their lights go out when they activate the steam wand please?

                  not really confident re the testing
                  yes, also ordered the thermal grease

                  Just to clarify, when selecting boiling water all the lights bar the power light go out, when selecting the steam wand no lights go out...

                  Comment


                  • #10
                    Woops! My turn to get my wires crossed!


                    This is correct -
                    boiling water all the lights bar the power light go out, when selecting the steam wand no lights go out...
                    I'm afraid I interpreted "boiler water" as "steam boiler"

                    Sorry about the confusion, you're still on track Terry, although I would still be happier with some meter testing to confirm the diagnosis before swapping out parts.

                    BTW, wonder where you are located as I would be happy to check it for you if you were nearby.

                    Trev

                    Comment


                    • #11
                      you're too nice Trev, I'm in Melbourne
                      its not out of the question, I do have a tester....

                      Comment


                      • #12
                        Earlier mention of measuring thermistor resistance roused my curiousity about the possibility of doing it without unplugging it from the control board and still getting an accurate reading, so I decided to document my results.

                        The first step I always take before removing the covers is to unplug and lock up the power cord in the modified plastic pill bottle I have made. I don't free it until I have put the covers back on.

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                        I have found that the back plastic cover can be removed by only removing the 4 screws and juggling it out from behind the door. This reveals the back of the control board.

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                        With the meter turned on I join the probes and check that the reading changes from "OL" (open circuit) to a low reading of 1 or 2 ohms. I could zero it but don't usually bother unless planning to read a low resistance.

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                        More next post ....

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                        • #13
                          The steam thermistor plug is the pair of pcb pads just to the left of, and below, the lower left cover screw head. With the points of the meter probes pressed firmly to these pads I get a reading of 97K ohms (97000 ohms).
                          This seems about right in view of the fairly high ambient temperature. I think the specified 100k ohms is at 20 deg C.

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                          This photo shows the circular orange (brown?) thermistor probe attached to the side of the steam thermoblock in the top RH corner with its two white leads tied to the wiring loom down to the control board. The white smear around it is the thermal grease to provide good heat transfer.

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                          I considered warming the thermistor with a hair dryer to see if it's resistance dropped but was running out of time, so I simply replaced the cover and freed the power plug from it's lockup.


                          Please note - I strongly recommend that anyone without the appropriate skills does not attempt working inside the machine as a mistake could prove fatal.
                          With the power cord plugged in there are many exposed points at mains potential, including the back of the control board.
                          Sorry about bringing this up all the time but I don't think the risk of death or injury is worth the $100 or so it would cost to have the machine repaired professionally!

                          Trev

                          Comment


                          • #14
                            you're a legend Trev

                            thanks for the info and photos, brilliant
                            my steam thermistor arrived today, will attempt this when I am sober

                            ps its not the money for repairs that bothers me its the time and time i'm without a coffee machine...especially this time of year


                            I'll keep you updated....

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                            • #15
                              OK, I failed right from the start

                              cant work out what cover you are talking about removing? Back plastic cover? I assumed you meant the silver plastic cover above the water tank [and below the filling lid/flap
                              but this has 3 screws and once removed I still cant pull it off. Also looking at your photo Attachment 11244 I cant place it on my machine?
                              I don't even see how to remove a side cover...oh the shame

                              epic fail

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