Serviced espresso machine is serviced
All kinds of replacement parts for things have come in over the last few days, including new Tempest cells to rebuild the battery pack for my main UPS, and service parts for the Gaggia espresso machine.
The Gaggia had two problems. First, it had begun leaking significantly between the filter holder and the brew head; and second, it had recently become very erratic about producing a consistent supply of steam for the milk steamer/frother. Given that one of the neon indicator lamps in the main switch mostly stopped working (it would sometimes blink on for a moment) some years back, which I had always attributed to a loose connection¹, I'd assumed the most likely cause of the steam pressure problem was that eleven years of use had simply worn the contacts in the steam switch until it wasn't making good contact any more. I've tried previously to servide the switch, but couldn't figure out a way to get the switch apart without breaking it. So, given that we have a little extra cash on hand for once, I spent fifty dollars or so on a new main switch, a new filter holder gasket, and a blank 'filter' for back-flushing.
Swapping out the main switch was a trivial job, requiring only care in making sure all ten connectors went back onto the switch in the right places, a problem simply solved by moving connectors over from the old to the new switch one at a time (since the wiring harness is long enough to take the switch out without having to disconnect the harness first). The gasket was a bit more of a problem, partly because it requires disassembling the brew head, partly because the old gasket had become so hard I couldn't get the point of a tool into it to pry it out. I eventually resorted to driving two drywall screws into and through the gasket (which is a ring 58mm in diameter, 8mm wide by about 9mm thick) and using them to effectively push the old gasket out from the back. This worked, even though the gasket had become so hard that it fractured at the screws instead of bending.
Of course, having the brew head completely stripped down again was a perfect opportunity to scrub it spotlessly clean with a fine stainless-steel-wire brush before reassembling it. The new gasket slipped in with just finger pressure. With a new filter gasket and new main switch, and a thorough cleaning, it was all ready to go again.
I will observe for the record (purely for academic interest, of course) that the first doppio cappuccino of freshly ground Kenya AA coffee out of a freshly cleaned and serviced Gaggia espresso machine is very, very good.
[1] Since neon lamps contain nothing that can wear out, they have an effectively infinite service life short of either mechanical breakage of the bulb or a lead wire, the neon² diffusing out through the bulb, or the electrodes eroding away - either of which takes a long, long time³.
[2] Technically, classic red neon lamps normally contain a Penning mixture of 99.5% neon and 0.5% argon.
[3] Unless too much current is being driven through the lamp, in which case electrode sputtering can become a problem.
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