# Nuova Simonelli Maxi



## dblshotmike (May 28, 2013)

I recently bought a 2group Simonelli maxi and it is in need of some serious TLC, once plugged in it works and starts up and produces a serious amount of of steam but no water comes through the group heads and the pumps just turns and turns but nothing really happens. So I switched it off and began to strip it. I was inspired by a post I read on Home Barista.com where a guy totally stripped it and reconditioned it.

So I began taking the whole front end off groups heads and screws with the front ends copper pipes. There is quite a bit of scale in it, so I presume that is what is blocking the valves etc...

I am by no means a coffee repair guy, however I love these machines and have always wanted to strip a machine down and start again. So I have begun this project.

Very nervous and have taken lots of pictures so that I can hopefully remember which pipe goes where.

Can anyone help me where I can get some critic acid to clean the copper? And when I have the powder what is the ratio to water?

Here are some initial pics:


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## DannyMontez (May 19, 2014)

Good luck! Looks like quite a task!


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## dblshotmike (May 28, 2013)

Cheers Danny! The problem with it taking too long to fix is that I forget where everything goes back


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## DannyMontez (May 19, 2014)

Lots and lots of photos then I reckon!


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## funinacup (Aug 30, 2010)

Nice one Mike. I find them fairly easy to strip down and all the screws are exactly the same which makes life easier when it comes to reassembling.

Espressotechno recommended the use of 'phos' or phosphoric acid before and it's meant to work really well. I used Calcinet as it's pretty strong and it stripped a lot of scale off with no agitation.


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## dblshotmike (May 28, 2013)




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## coffeechops (Dec 23, 2013)

Another restoration thread! Ace 



dblshotmike said:


> Can anyone help me where I can get some critic acid to clean the copper? And when I have the powder what is the ratio to water?


eBay. Should be about £10 per 2 kg ( eg here: http://www.ebay.co.uk/itm/201077770409 )

Concentration is not too critical - about four tablespoons per litre is strong. It should be food grade, so when mixed, taste it - it should be like strong lemon juice.

That said, I'd highly recommend Phos too, it's quicker, kinder to the copper and fewer salts (copper sulphate etc) produced to be scrubbed away afterwards.


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## dblshotmike (May 28, 2013)

Cheers for this. Can I re-use the concentrate for more parts or once used that's it?


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## coffeechops (Dec 23, 2013)

'Used' is relative - the acid is slowly neutralised by the calcium carbonate, so the acid concentration/strength falls slowly. When it stops dissolving quickly enough, discard it.

With Phos being a liquid, I think it's a 1:4 dilution ratio with water (espressotechno knows for certain).

Loads of pics please!


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## dblshotmike (May 28, 2013)

Will do, unfortunately didn't take enough of the state it was in when before some of these pics. But it's in pretty bad shape. There is a mixture of coffee and milk all over the base tray and just generally she is sad! Hopefully can restore her to former glory. I think it'll end up in my kitchen and not in our coffee shop


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## espressotechno (Apr 11, 2011)

Dilution for phos. is usually 1+4. Use a plastic dustbin as your soaking tub. Discard the solution when it stops fizzing...then mix up another batch as necessary. Wear rubber gloves & old clothes !

Janitorial suppliers usually stock "Phos" in 5 litre bottles.

When dismantling the brass & copper joints, use a hard point to scratch-mark & code the connections + lots of pics.


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## dblshotmike (May 28, 2013)

Anyone know much about these flow meters? I can't get them apart. Is there a trick to it?


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## dblshotmike (May 28, 2013)

Anyone know why this gauge is measuring between 4 & 5 bar? There is no water mains attached to it.


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## funinacup (Aug 30, 2010)

Could be a dodgy gauge, or it might reset once it's been off and put back on again with pressure in it.


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## dblshotmike (May 28, 2013)

I replaced the solenoid valves both on the cold water inlet and the group heads. Fired her up and away she went! Got to proper temp but saw that she had sprung a few leaks so I turned her off and when it had cooled down went to tighten it all up. On of the leaks was on the inlet to the pump. So off came the pump to get in there and tighten it up. Put it all back together and plugged her in and now the pump won't switch on to fill the boiler with water, any one got any tips or things to look at? I took the probe out that goes into the boiler and that didn't look to bad which was a relief







but took some steel wool to it and cleaned it up, tried again... Pump still won't come on to pum the water.

Can these motors just go so easily? I can't believe I am this far and now this.

Please if anyone can help and offer assistance that would be so helpful


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## funinacup (Aug 30, 2010)

Find the plug on the wiring loom that powers the pump and put an ammeter on it to see if theres power going to it.

If there is, then you could test continuity across the capacitor (white or silver cylinder) / ensure the shaft is moving freely (but you should probably still hear a sound even if the shaft wasn't turning)

Capacitors are cheap so if its dead then it's a simple fix. If there's no power going to the pump from the board then you have a fault at the board. I had the same problem on an Aurelia and got away with changing the 16a relay on the board.


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## dblshotmike (May 28, 2013)

Thanks, will check that. Got a mate coming with a meter to help me check it. Will feedback to you guys. Pump turns absolutely freely and fine as well as the motor.

So I have. A feeling it's not getting power all of a sudden. Could it have anything to do with the two way cold water solenoid valve?


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## Scotford (Apr 24, 2014)

Quite a task, well done and good luck with the rest.


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## dblshotmike (May 28, 2013)

Ok, so after a lot of back and forth and testing @espressotechno came to the rescue and helped me with going through some possibilities. Turns out it was the fuse on the Pc board. Replaced that and voila she fired up and the pump worked and the boiler started heating up as its all supposed too and then black out! It trips the main board in the house! Put the circuit breaker back up and try again! Whack out!

Any tips what could be causing her to trip the mains power at a certain temp?

Mike


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## DannyMontez (May 19, 2014)

Oh dear....


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## dblshotmike (May 28, 2013)

All sorted now and she fires up and gets to temp but when I press one of the buttons to dispense water on one of the group heads I pop the fuse on PCB. The other group works fine.

Can anyone offer any help? Maybe know who can check the board for me to make sure it's working ok.

M


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## coffeechops (Dec 23, 2013)

Measure resistance of the 3-way group solenoid valve coils - if they're different then it's likely one is shorted. Check for shorts in the wiring to each valve. Repeat for group buttons.

If no multimeter to measure resistance, it'll cost you a few fuses:

Swap the two 3-way group solenoid valve coils, and see if the fault moves with the valves.

If it does, it's the valve; if not, do the same with the wiring at the PCB end (plug group one into group two and vice versa, assuming they are identical).

If the fault moves then, it's the wiring. If it doesn't, then do the same with the group switches (though I'd say unlikely these would cause the fuse to blow) and group switch wiring.

If it still doesn't move, then it's the PCB.

My money is on the group valve coils.


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## dblshotmike (May 28, 2013)

Come across another problem with this machine







when pulling the shots, the pump goes but it fills the boiler as well as coming through the group head. But the boiler over fills







any advice?

M


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## funinacup (Aug 30, 2010)

I believe that's a dodgy solenoid on the inlet. Saw a similar problem with a domestic machine recently. Water was coming into the machine and through the HX but the first solenoid was passing so filled the boiler at the same time.

Bit vague sorry, but hope it helps.


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## coffeechops (Dec 23, 2013)

dblshotmike said:


> Come across another problem with this machine
> 
> 
> 
> ...


Does it fill normally if you draw water off via the hot water tap?


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