Under the Hood

A look inside the heart of a domestic Gaggia espresso machine.

Under the Hood

altYou wake up early, trudge to the kitchen and flick on the boiler. By the time you are out of the shower, your girl is piping hot and ready to serve (an espresso!). You pause just long enough to prepare and savour your morning indulgence, wondering if perhaps today you have enough time for a second. All the while, you remain blissfully ignorant of that hidden fear.

That fear that comes from time to time, when you wonder what you'll do if something goes wrong. The inevitable day when your precious cries cold water, won't steam, or fails to light up at all. You are dutiful in the usual preventative maintenance: cleaning, flushing, decalcifying, but what about when your darling needs a simple repair?

[See another short article for a refresher on disassembling the group head for cleaning or gasket replacement.]


What about Light Repairs?

Ok, so it happened to me. Gaggia pumped out my daily espresso, like the little trooper that she is. Her last call of duty was to prepare a latte, after which she had been prudently turned off -- a little habit of mine to prevent the possibility of a dry boiler and overheating.

Imagine my chagrin when she poured warm water after fifteen minutes. Chagrin, and some surprise - it was working an hour ago! No heat and yet the pump works. I try the steamer just to be sure: still no heat. Ok, so I'm thinking that I have somehow blown my thermal fuse. I'm not quite sure how, but that's what it looks like: a working pump and no heat from either brew or steam settings typically means just that. I pull out a multimeter to confirm. Yes sir, the fuse is dead.

What a second, you say, how did you get inside the machine? I didn't know either, but it's actually very easy. The Gaggia Espresso's top cover will nonchalantly flip up from the back, pivoting over the front. It catches only slightly on the water chute. Within the chute there is a screw that may need to be removed to release the top (mine does not).

altOnce inside, the apparatus responsible for the magic of your daily elixir is laid out in plain sight [photo left]. The experience is almost anticlimactic. The orange ulka pump is found at the back of the machine, while several coloured wires attach at various points around the boiler, denoting the external heating elements and the two thermostats. Bundled along the top of the boiler, on the left-hand side, is the fuse.

To the left and right side of the boiler, the smaller grey and orange connectors connect the two heating elements to the circuit. The larger connectors join the two thermostats to the circuit: the brew thermostat is found on the bottom left side of the boiler; the steam thermostat on the top of the boiler.

The grey wires are attached to the thermal fuse before joining with their bundled brethren emerging from the switch-block. If the fuse opens (blows), the heating circuit is disconnected and will not function. You won't get any heat, but the switch indicator lights and pump should still activate. If a particular thermostat goes, it typically only affects that specific function.