I think I can do that at least. I'm guessing I need to cut the shrink-wrap tubing to unplug the the connectors, then test the resistance/continuity across the fuse.

Or trace the wires to a point where all you do is unplug.

Ah that would work too---however one of the two wires coming from the pressure-stat end of the fuse goes to the vibratory pump, which is deep in the middle of the machine and really hard to get to So if all else fails i'll unplug at the fuse and buy some shrink-wrap tubing tomorrow.

leo

And, it looks like the continuity across the fuse is infinity---the needle doesn't budge. So the fuse is shot, and I should order a new one from chris' coffee?

this is it i assume:

http://www.chriscoffee.com/products/hom...hermalfuse

Well, I just replaced the thermal fuse, and covered up the terminals (with electrical tape, my local hardware store didn't have any shrink-wrap tubing...). The continuity across the new fuse was 0, so I think it is ok?

Anyway, I hooked the machine up, dropped the tubes in some water, held down the water-check button, and turned it on. The pump didn't engage immediately, like it used to. In fact, nothing much seemed to be happening. But the heater was slowly working, I think. However, after maybe 25 seconds I felt that something was wrong, so turned it back off.

After unplugging it, and poking around, the thermal fuse leads were *hot*---something that doesn't seem right. Even after 25sec of usage, the leads were quite warm/hot to the touch. Is that normal?

looks from the deposit from the boiler's pipe that you have scale to address

I will descale it, but I don't really understand why that would be the problem here. The fact that the thermal fuse blew, and that now there is power again to the heating element, seems to imply that the major issue was the fuse itself. Sure, the machine could use a descale (which I will do shortly). But it should at least be back to it's working self as it was before the fuse blew.

However, my question was partially also about the expected behaviour after I re-plugged in the fuse---is it normal that the leads on the ends of the fuse get so hot? I'm still puzzled why the pump doesn't come on for ~3-4s right when turning it on (which is what it used to do), but the heating element is producing heat (at least, electricity gets there).

cheers,
leo

No, the hot leads are not normal. Warm maybe, but not hot. Do NOT power the machine up again. Something seems amiss with the autofill circuit which you noticed a while ago.

I believe it is time to check & see if there is any water in the boiler. Remove some convenient top fitting and probe with a wooden dowel - machine unplugged.