# Gaggia Classic without water tank, but with fixed supplies for fresh and waste water, PID and manometer



## Matthias (Jan 26, 2020)

Hi,

I posted this in the best german coffee forum already, so this is something like a english version of it to this nice forum. I would like to introduce my Gaggia Classic Mods to you today (a bit detailed, sorry):










My goal was maximum comfort in the smallest possible space. In the standard "open" tank I occasionally found a mosquito or dust, which I found really unpleasant. To change the water and especially to clean the tank after every break of a few hours or days is just too much effort.
Standard fixed water machines are either big or expensive or both. Something like this should also be possible with the Classic. We don't drink a lot of espressi, so before there are any questions: I clearly did this mainly because I enjoy learning and making things work!

It all started with a Silvia steam wand. Then I upgraded a PID with "pre infusion" and shottimer (actually only because of the shottimer and the omission of an extra clock) and put it on top. The Shottimer is also very practical for "de-steaming" because the water runs through 30s and you don't have to worry about it any longer. After that I reduced of the brewing pressure like shown in a lot of threads.

Some time later I started the fresh water supply and led the water from the water pipe via pressure reducer and John Guest parts to the machine. I took the tank out of the machine, sawed off the tank refill, put the pump with L-pump brackets horizontally so the connections fit better.










A special elbow for the pressure-proof connection to the hose nipple of the ULKA pump is attached to the pump. From there it goes on via a 1/8" connector to the Teflon hose and then down into the former tank room. Down there I drilled a hole into the machine to the rear and installed a solenoid valve with device connection. The whole then with a transition piece to the pump inlet connected. The solenoid valve gets current like the pump, so that the valve closes automatically when the pump is without current. Works perfectly!

The water return line of the overpressure valve also leads into the tank, I put this with a Y-piece into the drip tray, where the water runs off now alternately with the surplus of the magnetic valve. The reduction of the brewing pressure also leads to an increased water drain (excess pressure) into the drip tray, which makes emptying the drip tray more frequent.










After removing the tank, the machine is of course "very open" towards the front, so I had a suitable 90° stainless steel plate with cut-outs made, which now also accommodates the PID and a brewing pressure manometer. But I have not connected the latter yet. I find the PID on top or on the side very unattractive. The PID is connected via a plug/socket connection, so that you can pull out the sheet metal and "unplug" the PID. The drip plate of the Gaggia is quite small, and of course water splashes on the new stainless steel plate, just like before on the plastic tank. Therefore I moved the sheet 1cm to the back and made a lightly tinted plexiglass cover in front of it, which is closed with a piece of shower sealing lip at the bottom and held (provisionally) with a small magnet at the top.










In the next step I tested how the water drain works best, in my opinion water sticks very well everywhere and only runs off when it gets some pressure. Therefore a horizontal outlet to the back (above the tank bottom) was out of question. Especially not, because then you would always have 5-10 millimetres of water in the drip tray due to the lower rounding of the drip tray and the edge of the screw connection itself. So I drain vertically downwards, which means the machine has to be raised a little bit. In my case by 30mm with four nice fitting door stoppers Makes almost more out of the machine than original as I think. In this 30mm ground clearance the drain had to be realized, which I succeeded after some research on parts:










First I decided to go for 3/8" because that was the maximum I could get down to the 30mm. In the bottom of the drip tray a hole has to be drilled of course. Into the hole comes from above a reducer 3/8" external thread to 1/4" internal thread, but not a normal one, but one from the photo supplies. This has a slit at the top, so that a) the water does not have to remain 1-2mm in the bowl, but can run off "at ground level" and b) one can tighten the whole thing somehow.










From below comes a seal and then a brass elbow with 3/8" female thread against it (is only about 28mm high, fits exactly ) ), which has a 3/8" external thread on the other side. For this part I had to remove a corner at the bottom of the gaggia, so that the whole connection has a useful place. On the external thread again a 3/8" sleeve is placed. On the sleeve a transition piece 3/8" external thread to 1/2" external thread. Between each of them rubber gaskets. On the latter I put a normal half inch device drain hose directly. I have read here about various drain problems and wanted to put something behind the kitchen that is not too thin afterwards.

The drain hose runs through the kitchen worktop (together with the John Guest hose for fresh water, of course) and then runs down a slope about 2m behind the kitchen (underlaid lengthwise so nothing can sag) to the sink where it drains into the siphon together with the dishwasher and sink.










Conclusion:
- The little Gaggia can be technically converted in this way quite well .
- Of course, it cost me most of all: time! As there are no manuals or parts lists for it, and most of the time I only heard the argument that the machine is far too small for all this anyway... so I'll publish this here, if anyone else wishes to do something alike. It was quite some effort to find all the information and parts and make everything fit. This hobby energy I gladly invested. Fortunately I was already educated for working on electrical devices, and you need some manual skills.
- The fixed water supply works really nice!
- The used water drainage also works very well, but there is always a small layer of water sticking to the bottom of the drip tray (even without coffee remainings), simply because there is no reason for it to run off, because the drip tray itself has no gradient big enough to overcome the adhesive properties of the water. The drip tray must of course be taken into account when cleaning the machine in general.
- open points: Connect manometer, hold transparent panel differently and:
- In winter the fixed water is quite cold, which is on average rather at room temperature for the original tank, except for the first time after filling. I could imagine that this could be a point of criticism for the small boiler, I have to measure how the PID and everything reacts to this when I put the tank in the tank

Perhaps some people will like or benefit from this report. If you find some typos or something, please send me a PN.

Many greetings
Matthias


----------



## davewuff (Oct 26, 2012)

Great work there Matthias. I applaud your ingenuity! Maybe you can find a market for these?

I've often thought there might be a way of moving the water filler to the rear so the PID and pressure gauge could be put into the body.

Anyway, welcome and great work.


----------



## Zeak (Jun 12, 2017)

This is amazing! Don't think I'd do this mod, but it's commendable for sure.


----------



## ThePeginator (Dec 17, 2019)

This thread is ace.

The only thing I thought you could have done differently is you could have plumbed the 'waste' outlet of the OPV valve, using a T piece, back to the inlet of the pump to reuse that water instead of feeding it into the drip tray. I guess with the machine being plumbed in it doesn't matter that much.

What did you use for the extended feet? Emptying my drip tray is driving me mad so I'm toying with the idea of doing something similar, all be it into an external bottle instead of mains as my classic is on an island with no mains water/waste.

I also might remove the water tank and plumb it direct from an external bottle of water, and if I do I might move the PID the way you've fitted yours.

Sent from my iPhone using Tapatalk


----------



## Matthias (Jan 26, 2020)

Thanks for your replies.

You are right - i thought about where to put the OPV outlet to, but actually I was not sure about the pressure situations and I didnt want to interrupt to much and also I was not sure about "water behaviours" so i didnt want to have any "old water" withour pressures in the machines pipes. I think if I connect it to the water inlet of the pump the higher pressure of the main water (about 1bar) would press against the opv valves outlet which might be not good for some reason. Actually this is a question I would like to learn more about.

The extended feet are actually stainless steel door stoppers/doorstops with Ø30mm and wall distance 30mm (in my case table distance)


----------

