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Gaggia Classic - No Water through Group head

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  • #16
    Just a quick word of caution re the above circuit diagrams. The pictorial diagram shows wire colours that are incorrect on some models I have seen.

    Over time Gaggia have changed the colour of some of the wires. Most of those I have seen are completely wrong by Aussie standards.
    Almost opposite of what we use here, though I have got one very old one that is at least partly correct.

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    • #17
      Originally posted by deegee View Post
      Just a quick word of caution re the above circuit diagrams. The pictorial diagram shows wire colours that are incorrect on some models I have seen.

      Over time Gaggia have changed the colour of some of the wires. Most of those I have seen are completely wrong by Aussie standards.
      Almost opposite of what we use here, though I have got one very old one that is at least partly correct.
      Agreed, I have had 3 classics and a coffee through my possession and they all were different colours!

      Even more of a reason to be familiar with how the electrical circuit actually works, not relying on colours of wires.

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      • #18
        Thanks for all the replies! This is odd, the wiring at the socket was incorrect, however all my photos show the brown wire at the top and the blue at the bottom. I googled images of the internal wiring of Gaggia Classics and saw a few photos with the brown wire at the top so I looked at the wiring diagram and this confirmed that the wiring was wrong. Checked my photos and the brown is at the top???? Anyway plugged it back in, the safety switch did not trip, powered it on at the machine, the power light turned on the first time that I have seen it for a split second, then the safety switch tripped!

        I've looked at the wiring diagram and the wiring looks ok, checked the wiring of my switches against your photos and all looked the same, difference is some of the colours of the wiring is different.

        The only thing I'm not sure of is the wiring of the pump. Would it matter if the wires were not connected to the correct terminals on the pump?

        Any thoughts on what to check next? Could it still be moisture? We have rain here today, so can't sit it out in the sun for a few days to dry!

        Cheers

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        • #19
          Originally posted by teds01 View Post
          Would it matter if the wires were not connected to the correct terminals on the pump? Could it still be moisture? Any thoughts on what to check next?
          To answer your questions :- The pump connections do not matter. It will work either way, and won't trip the breaker.
          It could still be moisture - can you beg, borrow, or steal a hair dryer, or better still, a heat gun ??.

          As Steve said, it was worrying that the RCD tripped as soon as the machine was plugged in.
          It is still worrying that it now trips as soon as it is turned on.
          But my biggest worry is that the only testing we can do is change something, then see if the breaker trips, or not.

          There are so many what-if's and maybe's here, and we are working from an unknown starting point.
          Seems like your socket / connections were reversed before you got it, so who knows what other changes have been made.

          I looked at the images on the web too. I only found one with the brown wire on top - most were blue, but it's not that important.
          If they were reversed at rear of the socket, and everything else was OK, the machine should still work anyway.
          The only problem I see is that there would be "live" wires and terminals throughout the machine with the switch off.
          This increases the number of places where moisture could be causing earth leakage which would trip the breaker.

          It's probably not what you want to hear, but if all else fails, you could try cutting all the cable ties holding the wires together, then following the pictorial circuit diagram, but ignoring the colours, physically trace every wire from end to end. The connections to the switch and the boiler must be exactly as shown. For 220/240V the elements should be in series. The wires to the solenoid should go to the two outer terminals. The wires to solenoid, the pump and the two thermostats can be connected to either terminal, as long as the right pair of wires are connected to each component.

          If every single wire/connection is right, then one of the components must be faulty, but then you still have to figure out which one.

          Maybe you need to start a new thread asking if there are any CS's in your area with tech ability and test equipment, & willing to have a look at it.

          Unless it is fairly new, it may not be worth taking it to a pro to get it fixed. ( or shipping it to and from Brisbane )

          Cheers, D.G.
          Last edited by deegee; 23 October 2013, 12:46 PM.

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          • #20
            Thanks again for your help deegee!
            I'm assuming my wiring is correct and that there is moisture in the element. If I disconnect the elements and the machine does not trip the safety switch, would that indicate that the fault is only the elements? If so, I was going to pull the boiler out again and put it in the oven to dry out. I tried a blow drier for a bit, but it seemed tedious, plus it did not work.
            If this does not work, I'll start another thread! Cheers!

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            • #21
              First the answer to your question re the elements :- Yes if you disconnect the elements, and the breaker doesn't trip when you turn the machine on, then that would prove that they are the problem. Whether it is moisture in them is another question, but it is a strong possibility especially if you had a bit of overflow or liquid sloshing around while you were de-scaling the boiler.

              I just re-read your previous post (#18) and my last one, and there are a couple of points I think I should make clearer.

              In my earlier posts I was assuming (there's that dreaded word again!) that the wiring was correct before you dismantled the machine.
              That the breaker was tripping before you turned the machine on indicates that the blue & brown wires were reversed before you got it.
              After these wires were changed back, the breaker only tripped when you turned it on, & that is further proof that they were reversed.

              It also reverses one of my earlier conclusions - i.e that the fault/moisture must be in the socket or the on/off switch.
              Now that we know those wires were transposed, it means instead that the socket is definitely O.K.
              The problem is downstream from the on/off switch now that the blue & brown wires are where they belong.

              In my last post I said that if the wiring was all correct that one of the components must be faulty.
              This also includes moisture in any of the components.
              One of the thermostats was loose too, so moisture could have seeped into one of them too.

              There is a way to progressively test each of the components sequentially - I will send you a PM about this soon.

              Cheers, D.G.

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              • #22
                Great, thanks for that D.G.!

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                • #23
                  Update on machine tripping safety switch. If you have pulled apart your machine and cleaned your boiler and then after reassembling your safety switch keeps tripping when powering the machine on, it is a possibility that there is moisture around your elements that is causing the problem. To test, make sure your machine is unplugged from the wall, disconnect the four wires to the boiler element. Turn on, if the Safety Switch (RCD, GFC) does not trip then it's a good chance that it is your heating elements (2 U shaped things externally on your boiler. To fix this I pulled the boiler out, took off the thermostat and steam valve, put the boiler in my oven for 1 hour at 150C.

                  Reassemble machine, no longer tripping the Safety Switch.

                  But now, my initial problem continues, no water through the group head.

                  How can the solenoid coil be tested?

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                  • #24
                    Reassemble machine, no longer tripping the Safety Switch - - - HALLELUJAH.

                    But now, my initial problem continues, no water through the group head - - - Bummer

                    How can the solenoid coil be tested? The obvious answer is with a multimeter, but I'm pretty sure you don't have one.

                    However there is another way. As usual disconnect the machine first, and Be Careful !!
                    Disconnect the pump, & tape the terminals. Leave the top plate off and reconnect the machine.
                    Get a short ( 25 - 40cm ) length of plastic or DRY wooden rod - a bit of old broom handle or a wooden spoon will do.
                    Turn the machine on press one end of the rod to the top of the solenoid. Press the other end against your ear.
                    Flick the brew switch on, leave it on for a few seconds then turn it off. Repeat if necessary, listening carefully.

                    If the solenoid is operating you should hear a sharp click (or clack) followed by a faint humming.
                    If you just hear the humming, the coil is OK but the valve is stuck.
                    If you hear neither, the coil is probably faulty, but will need to be tested properly to be sure.

                    Cheers, D.G.

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                    • #25
                      Hi D.G.

                      I've got a multimeter. Would that be easier, just need to know what to test for with the solenoid coil.

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                      • #26
                        Disconnected the pump, taped the terminals, connected the power, placed a wooded spoon on top of solenoid, flicked the machine on (noticed a quick flash of spark from the front switch panel) turned the brew switch on and off a number of times, but no clicks or no hums. Solenoid coil dead?

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                        • #27
                          Originally posted by teds01 View Post
                          Hi D.G.

                          I've got a multimeter. Would that be easier, just need to know what to test for with the solenoid coil.
                          OK you need to test for resistance. Pop the connectors off the terminals and test across the two outer terminals.
                          You should get a reading that is a little over 1 K-ohm. Probably about 1.1 or 1.2 K.
                          It will probably be a lot lower or higher than that if it is cactus.

                          If your meter is auto-ranging it should be OK but if it has manual range selection, make sure it is set to K's as it may not give a reading if it is set to ohms, or to Meg-ohms.

                          Cheers.

                          PS It's not unusual to see a spark at the switch. You don't normally see it because the top is on and your head isn't usually in that position directly above it.
                          Last edited by deegee; 26 October 2013, 04:02 PM. Reason: PS

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                          • #28
                            Originally posted by deegee View Post
                            OK you need to test for resistance. Pop the connectors off the terminals and test across the two outer terminals.
                            You should get a reading that is a little over 1 K-ohm. Probably about 1.1 or 1.2 K.
                            No reading at all = cactus?

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                            • #29
                              Originally posted by teds01 View Post
                              No reading at all = cactus?
                              Yes, I'm afraid that's it. It must have gone open circuit, and will have to be replaced. As I said in an earlier post, the valve & the coil come apart, and I believe I have seen them sold as separate parts, but I can't remember where. You should ask around, because the complete assembly was about $90 last time I looked.

                              PS You could try Jaycar

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                              • #30
                                Will try and source a replacement part asap. Will let you know how it goes. I wonder if having the socket wired incorrectly damaged the solenoid coil? Thanks again for all the help!

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