Post By kaanage
Gaggia Classic - Off-grid Mods
I have a Gaggia Classic that's about 10 years old, still working well. I've just done a full strip down and clean out, replaced a few seals as required.
I'm building a cabin at the moment, which will be a weekender for a bit, but then will be our permanent home in the near future. Power will be from a solar system, which currently has a cheap 1000w inverter that may get upgraded in the future, however I hope to postpone this purchase as long as possible and perhaps not make it at all if we find we can manage it.
I've done a power audit on all my essential appliances, and the coffee machine comes in at number 1 at around 1.3 to 1.4 kW draw when the heating element is on. The pump itself is pretty low power, only around 60w.
We will have a wood burning stove that will be running most of the time, with a wet back and hot water storage, so we will have hot water more or less on demand, with the ability to bring this to the boil quickly.
So, short of upgrading the inverter or changing methods, my thought is to disable the heating elements and use boiling water off the stove instead of the normal cool water resevoir. I anticipate running the pump for a while to warm the machine and group up before brewing a shot. Milk would be done seperately by either a stove top boiler/steam wand, or by heating milk in a saucepan and using a plunger to froth.
Has anyone done this and have any comments based on exerience?
Can anyone point out any fatal flaws in this process? I'm slightly concerned that the reservoir, pump and intake tube might not be designed for the temperature, but I could potentially replace these parts with something that could if need be.
I'm aware of alternative method, so I'm not really looking for suggestions at this point. We have a large plunger and a 8 cup moka, but I've never been happy with the results from these. The Gaggia is pretty reliable and I know how to use it, so I would prefer to stick with this machine first.
Near boiling water passing through the vibe pump?
The water reservoir should handle it, although it could 'age' faster. The biggest problem is the pump. They're not designed to handle high temps. I guess there's an alternative pump out there, but it could be expensive.
Another option I've considered is disabling one of the elements, and perhaps insulating the boiler. Will be a longer ramp up time, but might be stable enough to do our morning coffee (2 double shots). Perhaps to assist with this I could adapt the pre-heating coil that lots of people do and run this externally to the machine, the idea being it's not connected to the internal plumbing of the machine, but allows me to pour boiling water through it to assist the one element get the boiler up to temperature. A double coil might allow me to do both, i.e. use on coil to assist warming the machine up, and the other coil is the typical preheating mod.
As far as I know, the heating elements for the 230v version is wired in series and the 120v is wired in parallel.
Is that not a simple matter of swapping some connections around to skip one of the elements?
Originally Posted by JojoS
Simple swapping yes but then you have to feed it with 120v if you are using a single element.
Originally Posted by pcqypcqy
If you put a power diode in series with the elements, you will reduce the RMS voltage by a half, reducing the power usage to a quarter of normal but this may make the heat up time a LOT longer. The inverter might not like the resulting current waveform, either.
Running across a single element would bring this up to half power but the elements probably weren't designed for 240V peaks
I would not recommend doing any of what I have posted