# Gaggia Classic crossed wiring?



## RedShanks (Feb 17, 2021)

Hello, everyone. Sorry to begin with a plea for help, but I couldn't think of another way forward.

I stripped down my Gaggia Classic (about 8 or 9 years old) to fit a new set of gaskets and to clean and descale the boiler. I have removed the boiler for cleaning once before without a problem, but this time I assume I've made a mistake with the rewiring because when I switch it on it trips a circuit breaker the house circuit board - the modern equivalent of blowing a fuse.

Of course I took the usual precautions - several photos and a simple little aide memoire diagram, but I've still obviously made a mistake.

I'm not expert enough to read a proper wiring diagram, although I know they're available, but I wondered whether anyone on the forum might be able to suggest how to solve this.

Thanks.


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## Alfieboy (Dec 26, 2018)

RedShanks said:


> Hello, everyone. Sorry to begin with a plea for help, but I couldn't think of another way forward.
> 
> I stripped down my Gaggia Classic (about 8 or 9 years old) to fit a new set of gaskets and to clean and descale the boiler. I have removed the boiler for cleaning once before without a problem, but this time I assume I've made a mistake with the rewiring because when I switch it on it trips a circuit breaker the house circuit board - the modern equivalent of blowing a fuse.
> 
> ...


 Is it possible the elements got wet? It's more likely than a crossed wire

You can test with a multimeter or better still a Megger

Neil


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## Michael87 (Sep 20, 2019)

It is quite common if you got water on the outside of the boiler to accidentally short the heating elements to the boiler body. That will trip your breaker when the machine turns on and starts heating.

One solution posted is to remove the boiler again and put it in the oven on low temp for a few hours to dry it out. Remove thermostats.


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## DarkShadow (Jan 14, 2021)

Posting pictures of all the wires will help us in aiding you where you may have gone wrong. How did you originally document your changes? Did you write on the pins?


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## RedShanks (Feb 17, 2021)

Uncletits said:


> Is it possible the elements got wet? It's more likely than a crossed wire
> 
> You can test with a multimeter or better still a Megger
> 
> Neil


 Thanks for the response. I suppose it is possible I got the elements wet. Having said that it's now been three days since I did the job, but maybe that isn't long enough for it to dry off. I have access to a multimeter but I wouldn't know how to conduct a test. But I do have an electrician friend who can probably explain.


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## RedShanks (Feb 17, 2021)

DarkShadow said:


> Posting pictures of all the wires will help us in aiding you where you may have gone wrong. How did you originally document your changes? Did you write on the pins?


 I did write on the pins the first time, but unfortunately that was a long time ago and I don't have the corresponding diagram. This time I did it with labels (masking tape, wrapped round each cable and marked with the position of the wire on and around the boiler).


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## MartinB (May 8, 2011)

Get a pic of the wiring up. Sounds like what happens with wet elements as per other replies.


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## larkim (Sep 3, 2018)

I had a similar issue when I reassembled mine. The approach I took was as follows (though take care with electrics!)

Unplug from mains & switch off mains socket

Remove two boiler heating elements from steam wand side only (i.e. disconnect just one heater element)

Switch on front of machine

Plug back into back of machine

Switch on power at the mains

If it trips, you know it's the heater element on that side. If it doesn't, you can try the opposite side only.

For me, it was the left hand side (when looked from above) that was causing the issue.

I googled a bit and someone suggested a potentially unsafe but effective route to try next, by removing the boiler earth connection, and repeating the same "switch on only at the mains without touching the Gaggia" route.

This worked to allow the heater element to warm up for 5 minutes or so, driving out the moisture. I carefully unplugged, reconnected earth etc, and this time it didn't cause the house RCD to trip and has been fine since.

Without heat you'll not drive out moisture from the connections, so for me it was either do that or put the whole thing in a very warm place for a while.

I should add I AM NOT AN ELECTRICIAN AND WHAT I'VE SUGGESTED MAY BE VERY UNSAFE but if you're the only person in the house and you only ever switch things on by turning on the wall power switch without touching the Gaggia I believe this should be risk free.


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## RedShanks (Feb 17, 2021)

Michael87 said:


> It is quite common if you got water on the outside of the boiler to accidentally short the heating elements to the boiler body. That will trip your breaker when the machine turns on and starts heating.
> 
> One solution posted is to remove the boiler again and put it in the oven on low temp for a few hours to dry it out. Remove thermostats.





MartinB said:


> Get a pic of the wiring up. Sounds like what happens with wet elements as per other replies.


 OK, I'll need to set up an Imgur account, or something similar.


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## RedShanks (Feb 17, 2021)

larkim said:


> I had a similar issue when I reassembled mine. The approach I took was as follows (though take care with electrics!)
> 
> Unplug from mains & switch off mains socket
> 
> ...


 Thanks Larkim. I'm very attracted to the wing and a prayer nature of this! The consensus here strongly indicates a problem with moisture rather than wiring, so I'm going to give this a go. Thanks to all who responded so far. I will let you know!


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## RedShanks (Feb 17, 2021)

larkim said:


> I had a similar issue when I reassembled mine. The approach I took was as follows (though take care with electrics!)
> 
> Unplug from mains & switch off mains socket
> 
> ...


 PS: Which are the connections to the heating element? Are we talking about the pins on top of the boiler?


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## larkim (Sep 3, 2018)

RedShanks said:


> PS: Which are the connections to the heating element? Are we talking about the pins on top of the boiler?


 Yes, at least that's what I assumed!!! As they are on the top of the "U" shaped heating elements on the exterior of the boiler.

TBH, you could skip the diagnosis and try the "unearthed" option and see if that avoids the trip first of all. I wore rubber gloves even though I wasn't touching the gaggia at all "just in case" and made sure my family weren't licking the copper pipes on radiators etc in case a fault went through the earth throughout the house.

Good luck! It only took 5 minutes of heating for me, and I was pretty certain that I'd allowed the elements to come near water after I'd rinsed out the boiler following some de-scaling with a brush.


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## larkim (Sep 3, 2018)

If un-earthing the boiler only doesn't work, you could try un-earthing at the rear of the Gaggia too - i.e. completely disconnect the house's earth from the machine. The earth cable attached to the "roof" of the Gaggia ought to (in principle) fnd the same earth fault I think if the top is in metal-to-metal contact with the chassis of the machine as the boiler isn't isolated separately (I don't think).


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## Alfieboy (Dec 26, 2018)

RedShanks said:


> Thanks for the response. I suppose it is possible I got the elements wet. Having said that it's now been three days since I did the job, but maybe that isn't long enough for it to dry off. I have access to a multimeter but I wouldn't know how to conduct a test. But I do have an electrician friend who can probably explain.


 They can be like it for weeks after

Please be careful whatever you try and if in doubt do not try it


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## larkim (Sep 3, 2018)

I'm hoping @RedShanks hasn't posted for a few hours because (s)he is in work and can't sort out testing our my approach, rather than lying electrocuted on their kitchen floor. Success or otherwise, post back with results!


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## Rincewind (Aug 25, 2020)

The only fault with the "advice" given ☝(i wouldn't state any of it on a public forum fwiw) is that *people can/do get side-tracked*, kids, pets, phone/other and that's when he/she could *forget* to "*re-attach that Earth wire/connection*" in either the plug/chassis.....*that's when it gets ugly*.

Accidents are a side-tracking waiting to happen ⚡⚡

Be very very careful. Always THINK SAFETY.


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## larkim (Sep 3, 2018)

Rincewind said:


> The only fault with the "advice" given ☝(i wouldn't state any of it on a public forum fwiw) is that *people can/do get side-tracked*, kids, pets, phone/other and that's when he/she could *forget* to "*re-attach that Earth wire/connection*" in either the plug/chassis.....*that's when it gets ugly*.
> 
> Accidents are a side-tracking waiting to happen ⚡⚡
> 
> Be very very careful. Always THINK SAFETY.


 I found the suggestion on another public forum with similar warnings attached. Happy to delete the advice if anyone thinks it isn't appropriate (though it worked for me!)


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## RedShanks (Feb 17, 2021)

larkim said:


> I found the suggestion on another public forum with similar warnings attached. Happy to delete the advice if anyone thinks it isn't appropriate (though it worked for me!)


 Larkim, sorry I dropped out for a while... various commitments, including taking the car for an MOT. I would like to have been able to just focus on the Gaggia, but interruptions were inevitable. Anyway, thanks for the advice and please be assured that I am still alive and kicking (mostly the cat, out of sheer frustration).


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## Rincewind (Aug 25, 2020)

@RedShanks









i hope not...cats are wonderful....glad your still alive :classic_smile:


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## Deegee (Apr 5, 2020)

Hi there @RedShanks I've done the same with my old Evolution, it appears that either the white insulation material absorbs water or water gets between the element pins and the insulation via capillary attraction, the end result being the house electrics trip out due to an Earth fault. If possible take the top off the machine and put it in the airing cupboard or a very dry place for a week or two while life takes over, chances are it'll dry out the water.

What you shouldn't do, is go into a wire changing frenzy, forget where you started and then start doubting the way you marked the wires. I'm not saying I've done that of course, just that it can happen.....


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## RedShanks (Feb 17, 2021)

Deegee said:


> Hi there @RedShanks I've done the same with my old Evolution, it appears that either the white insulation material absorbs water or water gets between the element pins and the insulation via capillary attraction, the end result being the house electrics trip out due to an Earth fault. If possible take the top off the machine and put it in the airing cupboard or a very dry place for a week or two while life takes over, chances are it'll dry out the water.
> 
> What you shouldn't do, is go into a wire changing frenzy, forget where you started and then start doubting the way you marked the wires. I'm not saying I've done that of course, just that it can happen.....


 Thanks for that, DeeGee. I followed up all the tips from yesterday by taking the boiler out again and putting it in the oven for a while on a low heat (as mentioned in one post). It was in for about an hour, but when I took it out I could still see signs of water in little crevices. This is one obstinate machine. I appreciate what you're saying about not being too cavalier or over-enthusiastic with the wiring. In fact the more I considered it the more I thought I couldn't really have made a mistake with it and that the problem must be shorting out due to water ingress. That was the overwhelming opinion on here and it was a revelation to me. I realise I must just have been lucky last time I stripped it and descaled the boiler. Anyway, I've now got the boiler sitting on top of a radiator, heating element side down. I'll turn it over and give the other element a blast before I reassemble it tomorrow. I can almost taste the coffee.


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## Deegee (Apr 5, 2020)

Trick is to have the connector pins uppermost so the water can escape as vapour. It'll take a little while to clear it, it all depends on how much is in it, I didn't think it could happen and regarded the white insulation as a bit like spark plug ceramic - waterproof, and so happily submerged it to wash the descaler out, sadly it all went Pete Tong when I reassembled it, thought sod it and put the poor old Evo in a dark corner of the utility room and forgot about it. I only dragged it out again because my Brother wants to try a 58mm machine so I thought I'd have a look at seeing what was wrong and if it was fixable, I'd seen plenty of posts detailing this issue over the last year and yes, it was my fault all along, doesn't help the feeling I had when everyone was moaning about pinging the RCD multiple times last Christmas though. As it turned out I bought a new machine before the rush at lockdown, so it did me a favour tbh, but I owed the Evo some love for my mistake so fingers crossed it works ok by the weekend!


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## RedShanks (Feb 17, 2021)

Deegee said:


> Trick is to have the connector pins uppermost so the water can escape as vapour. It'll take a little while to clear it, it all depends on how much is in it, I didn't think it could happen and regarded the white insulation as a bit like spark plug ceramic - waterproof, and so happily submerged it to wash the descaler out, sadly it all went Pete Tong when I reassembled it, thought sod it and put the poor old Evo in a dark corner of the utility room and forgot about it. I only dragged it out again because my Brother wants to try a 58mm machine so I thought I'd have a look at seeing what was wrong and if it was fixable, I'd seen plenty of posts detailing this issue over the last year and yes, it was my fault all along, doesn't help the feeling I had when everyone was moaning about pinging the RCD multiple times last Christmas though. As it turned out I bought a new machine before the rush at lockdown, so it did me a favour tbh, but I owed the Evo some love for my mistake so fingers crossed it works ok by the weekend!


 Thanks again, Deegee. I just turned it upright. The laws of physics obviously don't come naturally.


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## londonstuff (Apr 7, 2018)

I'd just add to this that what everyone is saying seems to be what I experienced as well. I gave my boiler a good dunk in Puly water as there'd clearly been a leak in it at some point. It tripped out the house three times in a week but seemingly came good about eight days later. Best of luck!


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## RedShanks (Feb 17, 2021)

londonstuff said:


> I'd just add to this that what everyone is saying seems to be what I experienced as well. I gave my boiler a good dunk in Puly water as there'd clearly been a leak in it at some point. It tripped out the house three times in a week but seemingly came good about eight days later. Best of luck!


 Thanks for that. The more input I get the more I'm convinced it must be down to this - a problem I'd never even heard of before. The only slight doubt I have is that I used a continuity tester on both sets of heating element terminals and got a positive beep both times. But perhaps continuity isn't affected by this. Or - just as likely - I don't know what I'm doing with the continuity meter.



londonstuff said:


> I'd just add to this that what everyone is saying seems to be what I experienced as well. I gave my boiler a good dunk in Puly water as there'd clearly been a leak in it at some point. It tripped out the house three times in a week but seemingly came good about eight days later. Best of luck!


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## PACMAN (Feb 11, 2021)

RedShanks said:


> The only slight doubt I have is that I used a continuity tester on both sets of heating element terminals and got a positive beep both times. But perhaps continuity isn't affected by this. Or - just as likely - I don't know what I'm doing with the continuity meter.


 That shows that both elements are not broken, ie will pass electricity - what you need to look for is the resistance (or continuity) from the pin to the metal boiler itself. As you already know there is continuity along the boiler elements, it doesn't matter which pin you pick, as long as you check both boiler elements. With the meter on resistance, you want infinity or whatever value you get when the probes are not touching anything. If you get any resitance reading, I'd suggest this is a bad thing, though I don't have a boiler here to check against to know what a 'good' value might be. Make sure your hands (or any parts of your body) are not touchign the probe pins when you check else it will read the resitance through your body! As ever, ensure no mains is connected when testing (but clearly if your boiler keeps tripping, this is not an issue for you!).


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## Michael87 (Sep 20, 2019)

Yeah. I am 95% sure you will find continuity testing shows a conductive path (beep) between element connector pin and the boiler body


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## Deegee (Apr 5, 2020)

@PACMAN is correct, the two pins at the top of the "U" shape should show continuity if you put a meter across them using the continuity function, there should be no continuity between any one of the top pins and the alloy boiler body, that would imply an element or insulation failure.

I haven't tested mine pin to pin to get an accurate resistance value, if it helps, I'll pull the top off and check for you, just reply if you need that info @RedShanks , just let me know if yours is a 1300w or a 1425w as I've got both here. Cheers DG.


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## RedShanks (Feb 17, 2021)

Deegee said:


> @PACMAN is correct, the two pins at the top of the "U" shape should show continuity if you put a meter across them using the continuity function, there should be no continuity between any one of the top pins and the alloy boiler body, that would imply an element or insulation failure.
> 
> I haven't tested mine pin to pin to get an accurate resistance value, if it helps, I'll pull the top off and check for you, just reply if you need that info @RedShanks , just let me know if yours is a 1300w or a 1425w as I've got both here. Cheers DG.


 Thanks for all the responses. That info might be useful, Deegee, if you don't mind the hassle. Mine's a 1300w.


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## RedShanks (Feb 17, 2021)

RedShanks said:


> Thanks for all the responses. That info might be useful, Deegee, if you don't mind the hassle. Mine's a 1300w.


 Come to think of it a reading won't help me. I only have the most basic Fluke T90 tester, so no display and no precise readings. So I wouldn't able to compare with your readings. However I've just tested with the probes held between heater element pin and alloy body and there's no beep from the meter. I've now put the Gaggia boiler in my central heating boiler cupboard, so it should dry out slowly.


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## Deegee (Apr 5, 2020)

No problem, just in case anyone else was following or someone comes searching in the future and wants the info, measuring across the pins on the elements one at time gave a reading of 22 & 23ohms, my machine was still warm (40°c) from this morning, so resistance may change a little with a cold boiler.

@RedShanks glad to hear you've got no leakage between the elements and the boiler casing, I double checked mine and there was no continuity at all either, hopefully it'll be together and working this time next week!


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## RedShanks (Feb 17, 2021)

Deegee said:


> No problem, just in case anyone else was following or someone comes searching in the future and wants the info, measuring across the pins on the elements one at time gave a reading of 22 & 23ohms, my machine was still warm (40°c) from this morning, so resistance may change a little with a cold boiler.
> 
> @RedShanks glad to hear you've got no leakage between the elements and the boiler casing, I double checked mine and there was no continuity at all either, hopefully it'll be together and working this time next week!


 Amen to that. But I will report back.


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## Rincewind (Aug 25, 2020)

Deegee said:


> a reading of 22 & 23ohms, my machine was still warm (40°c) from this morning, so resistance may change a little with a cold boiler.


 Yepp the *resitance will LOWER as the temperature gets lower*....the atoms don't vibrate as much (slow down as such) so therefore they don't cause as much friction/heat (resistance to electron flow) as they crash into any other atoms or impurities thereby effectively lowering the resistance of said item....lower the temperature to really really low values (think super-conductors) and then you'll find the resistance practically (almost) disappears....therefore MAXIMUM current can flow through said item.

Resistance is both good and bad...it depends on what you wanna do with it that makes it helpful/hindrance.


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## RedShanks (Feb 17, 2021)

Hi, All!

Thanks to everyone who pitched in with tips and info. Acting on all the input I took the boiler out again and left it on top of the central heating boiler in the boiler cupboard (effectively like an airing cupboard) for about 10 days or more. I just reassembled it, plugged it in, screwed up my eyes and switched it on, and... hey presto. Or hey espresso!

In the meantime I had adjusted the grind on my Iberital grinder. Anyone familiar with these will know that the adjustment is so fine and gradual that once you've got a grind setting you're happy with you really don't want to change it. But I did, rather recklessly. So I'm now struggling with the balance between grind and tamp, as the coffee is consistently a bit too bitter. But once I've got that right I'm back I'm business. So again, thanks to everyone.


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