Gaggia Classic - No Water through Group head

[deegee]

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.

[teds01]

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

[Steve82]

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.

[deegee]

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.

[Steve82]

It is worrying that the RCD is being tripped just by plugging the machine in.

I have attached the wiring diagram for the classic, if you cant understand it , probably best not to be messing with it and as Deegee said, get someone else who does to have a look.

ClassicCoffee_V220_Sae0299_Rev00.pdf

[deegee]

Would moisture in around the element/boiler cause the safety switch to trip even when the machine is not turned on but plugged in and powered on at the wall??

In a word, NO. The only place that moisture could do this, is in the socket at the rear, or in the machines on/off switch.

The blue active (live) wire should go straight from the socket at the back, to the machine's on/off switch. Until that switch is turned on there should be no live power anywhere else.

If it is moisture, I would suggest putting the machine out in the sun for a few hours, that should dry it out.

If that does not fix it, then I think that the fault must be in the socket (unlikely), the wiring or the switch.

If the machine is dry & the wiring is correct, a fault at the socket, or in the on/off switch are the only things I can think of that would trip the breaker with all the machine's switches turned off.

Re the light :- If the on/off light was short circuited, or earthed, it would trip the breaker, but only when the switch is turned on - not before.

Re the thermostat :- Some seem to get loose like yours did. I have seen a couple like that, but they still worked OK. I'm not sure if they screw together, or are a press fit. I didn't try to tighten them by twisting in case they are not meant to screwed. I fixed mine with a drop of super glue. But, for the same reasons as above, even if it is faulty, it should not be tripping the breaker with none of the switches on.

Now I know you took pics and labeled everything, and you triple checked them, but I'm still going to say please check one more time.

I have attached a couple of pics which show the correct connection of the most important wire - the active. It is blue, and runs from the Top terminal at the rear, to the Top Left terminal of the switch block ( looking at it from the front - top right looking from the back ).
The terminals are marked "A" and "A2" in the pics.

The third pic shows all the connections on the switch block as seen from the back. This machine was working OK yesterday after I replaced a blown thermal fuse, and I have not had any of the leads off, so it should be correct. It is also identical to my own working Classic so I'm sure that it is right. ( Mine is the one in pic 4 )

I can only suggest one simple test at this stage.

First turn the power OFF AT THE WALL AND UNPLUG THE MACHINE !!. ( Yes I know I'm nagging - but I've been zapped - it's not fun )
Remove the top spade terminal (A in Pic 1 ) from the rear socket and the brown wire below it.
Do NOT remove or unplug the yellow/green earth wires.
This will isolate the socket. Plug in & turn on the power point. If the breaker trips the socket is faulty.
If it does not trip ( and my guess is that it won't ) then socket is OK.
Turn power OFF, unplug the machine. Reconnect the terminals - blue on top brown underneath.

I started to suggest a couple of other tests, but it gets too complicated to do properly via the written word. If you can't find something from the photos, it really needs hands-on diagnosis by someone who has a circuit diagram, a multimeter and some technical experience.

[teds01]

Just another thought, I had the boiler sitting upside down filled with descaling solution. I had not removed the thermostats so the boiler was sitting on top of the steam thermostat. When I reattached all the wiring I noticed that the black plastic part of the steam thermostat was a bit loose. I was and am able to twist the plastic part of the thermostat maybe a bit less a quarter turn to tighten it.

Could this be damaged and causing the safety switch to trip? If I disconnect the wiring to that thermostat and turn it on, would that be a way of testing?

Thanks again!

[teds01]

Hi deegee,

I've gone over the wiring, I had labelled and photographed everything. I'm pretty much 100% certain that the wiring is correct, I've gone over it a number of times. I'm thinking there is moisture somewhere that is causing the problem??? All the connections seem to look ok. I tried another power cord and it still tripped the safety switch. Would moisture in around the element/boiler cause the safety switch to trip even when the machine is not turned on but plugged in and powered on at the wall??

Also, not sure if this maybe related but the light in the power switch has never worked, wondering if there maybe a fault within the switch?

Andrew1992, I had pulled the boiler out, dismantled it by removing the group head, three way valve, OPV and soaked everything in descaler, blew compressed air through it all and reassembled. But since then I can't even power it up to see if it will pump water through the group head. Will let you know how it goes once I figure out this power problem.

Thanks for all the help and suggestions!

[Andrew1992]

Did you try removing the three way valve??

I had the same problem with my Gaggia (and is a common problem with a lot of Gaggias)..I removed the valve from the group head and soaked it in vinegar to clear it out...works a treat now!

there is stuff on google re removing this valve but i can't locate any atm

[deegee]

If the breaker is a sensitive RCD type then moisture could be tripping it, but if it is the simpler current overload kind, the you have some other problem.

Don't want to seem too negative here, but when I have dismantled and reassembled something, and it trips a breaker or blows a fuse, I often find that it is operator error ( i.e. Me )

If it is still tripping the breaker after it's had time to dry out, you need to go back and check all the connections - very carefully.

The fact that it is tripping before you turn on any of the switches on the machine tends to indicate that the problem is in the power socket/terminals at the back of the unit or the connections from there to the switch or boiler.

It could be a fault in the switch or the boiler but under the circumstances, that is less likely.

D.G.

[teds01]

Bugger, I gave everything a good clean and reassembled it all, but when I plug it in the wall and turn the power on at the wall the the safety switch trips. This is even without turning the actual machine on???? I'm assuming there is moisture somewhere causing this as I have checked and rechecked all the connections. I had labelled each one and took photos of each wire/plug etc!!!

Will let it sit for the day and try later on. Unless someone can suggest another solution?

Thanks

[deegee]

I think you're right on both counts.

If there is no water return to the tank, especially with no flow through the group, it sounds like the opv is frozen shut and will need to be dismantled and cleaned to ensure that the bits inside are moving freely. It's not a difficult job, and is easier when the valve assembly is removed from the back of the head.

If both the pipe at the top and the small hole at the bottom are clear, then the 3way valve is almost certainly where the problem lies.
I have never had one out of a machine or pulled one apart, so I'm not familiar with the internals. I do know that they are made up of two sections, the solenoid valve itself, and the coil that actuates it. They can be bought separately if only one of them needs to be replaced.

All of the above assumes that the pump is actually working and supplying a good volume of water at good pressure, but if the water from the wand is a good strong stream, with some pressure behind it, then I think we can take that as a given.

I'm now going out for the day, and will not be back online til this evening, but will check tonight or early tomorrow to see how it went.

Cheers, D.G.

[teds01]

Hi Deegee,

No worries. Their is no water returning to the reservoir, so does that mean the OPV is not working?

I took out the boiler, and could blow air freely through all the holes. Therefore, would that mean the three way solenoid is faulty? The spring inside the valve all seems to move nice and smooth. That makes me think it is the solenoid coil????

I'll reassemble everything this morning and test.

So far I'm assuming the following:

OPV problem as no water returning to resevoir.

Three way valve problem as no water through to group head.

How's that sound?

Thanks again for your help!

[deegee]

I never expected the OPV adjustment would fix the group blockage, as I thought that was a separate problem, and still do. That was just to see if you could free it up, and get some water through the return tube back to the tank, which would indicate that the OPV was working.

As to the group head, there is something I had forgotten, so I have misled you. ( Sorry about that )
In a Classic, the pipe does not go direct to the group head, it goes via the 3way solenoid valve, which is what I overlooked, and your problem may be in that valve. With the valve removed, air blown into the pipe will come out of one of the holes at the back of the group head under the brass fitting for the valve. The other hole under that fitting goes to the small hole in the bottom of the head, and if they are both clear, then your 3way valve is not working, is blocked, or is jammed in the closed position.

In my defence I must say that it has been a while since I had a Classic apart, but at the moment I have a Gaggia Carezza in pieces on the workshop bench, and it doesn't have a 3way valve, so I had that in the back of my mind while making the previous posts.

Hope this is more help than my previous attempts.

Cheers, D.G.

[teds01]

Thanks again deegee, I tackled the OPV first and wound in the hex bolt in 4 turns. Initially there was some resistance but the bolt turned easier as I wound it in. I backed it off 4 turns and then tested. Still no water through the group head.

Next, I've just pulled the boiler out, the 4 bolts holding the boiler to the group head were quite corroded. One bolt was difficult to remove. On first inspection there is alot of white corrosion (calcification??) inside the boiler and a fair bit of loose scale and grit. I'm unable to blow any air through that tube you mentioned, so therefore I'm assuming it's blocked and see what descaling liquid I have and get it to work on the tube. Will report back later.

Cheers for the guidance!

I'm in Adelaide, thanks for the offer of the gauge, might try and have one put together to do some adjustments later.