Yes, I expected infinite resistance because the relay contacts would be "open". What value of resistance does your meter show when the leads are not connected to anything? What happens to the reading when you connect the leads to each other?

The pair of blue wires connected to the single terminal opposite the white PROBABLY go to the fill solenoid and pump and Gicar box - sort of like a daisy chain. They eventually connect to the terminal strip where the line cord enters the machine. This is very remote BUT unplug and then reconnect all the terminals you see that have the blue fabric wire WITH THE POWER OFF AND UNPLUGGED.

Here, of course, is where a wiring diagram is almost a necessity. What does your water reservoir switch look like? Do you take water from the tank or have you switched to direct feed?

I won't be home til this evening so I can't test anything right now. But as far as resistance on my meter - when the contacts are not touching anything I get a reading of 1, when connected together I get 0.

Alex.

Well, for some quirk, 1 on the meter = infinite. The readings were as expected, considering the situation with the machine.

If everything were operating normally, the readings would have been zero ohms when the power is on and the pstat is calling for heat OR infinite ohms when the power is on and the pstat is satisfied or any state when the machine is turned off.

Interim update...

Very busy at work lately - been exchanging emails but haven't been able to call Chris Coffee and speak to service while at home in front of the Izzo - until today (took the afternoon off specifically to deal with this).

Tim in the service department was kind enough to guide me through the internals of my machine and with his assistance we made some conclusions:

The Gicar seems OK
The pstat seems OK
The element seems OK

It seems that, as odd as it may be, the replacement power relay was also bad! They're sending me another one - one that they are going test in a working machine before it leaves. That way if my machine is still acting up with the new replacement we can be nearly certain the problem lies elsewhere. The reason that we still suspect the relay is that we've measured 115v going into it, and we've measured 115v coming out of it, but we do not measure voltage crossing through it.

I'll post here when the new part arrives.

Alex.

One additional thought. I used to work on Avionics in the Navy, and these intermittant problems can be a real bear (things like roll computer failure at 45 deg climb in excess of mach 1 - try duplicating that). The fact that you could bang on the relay and it worked, but wasn't the relay could indicate you have a soldered connector with a cold or failed joint. Can't tell from the pictures if the connections are crimped or soldered. If they're soldered and you can slide the plastic away from the pin you can at least visually inspect them. Good solder joints are shiny and will flow smoothly from wire to pin. Bad solder joints are dull and have a defined line where it ends, as opposed to flowing. If you can inspect that, you can also inspect the ends of the wires to see if they were cleanly stripped, or if some of the strands were cut when the insulation was stripped off.

Hope your next part fixes things.

Well I'm sitting around waiting for my new relay to show up and I'm finding myself bored. With all this talk about possible problems with my mechanical relay I decided to dig further into mine... well both of them - the one that was in the machine for over a year and the new one that is mysteriously exhibiting the same symptoms! I figured rather than pull my hair out, I'd pull the guts out of the relays and take a look.

I think I can now safely say - IT'S THE RELAY!!! The new part should fix me up. Here's a shot of the inside of my first one - Note the charred black contacts on the right:



Here's a closeup of those blackened contacts. I don't think power is getting through this build-up:



This is a closeup of the wire connecting the coil to the terminal on the outside of the relay:



This is the replacement relay. Here's a closeup of the same wire that's supposed to connect to the post below it. Clearly not connected at all - problem found!



After taking the time to disassemble the relays I thought, well, while I'm in here, let's see if there's anything to be done with these blackened charred contacts. I carefully took some 400 grit sandpaper and placed it between the two discs of each contact and gently polished off most of the crap that had built up, cleaned out any dust and residue, reassembled it and hooked it up. CLICK!!! I heard the relay inside! Measured voltage at the relay terminal going to the hi-temp (middle black one between the corner black and the white). The machine started heating up! But it faltered and didn't get through to full heat. I wasn't able (or didn't try hard enough) to remove all of the arced-on black junk from the contacts and so I think that's probably why.

I'm now doubly anxious to get my new relay from Chris's! I'm nearly certain that this problem is solved!

Alex.

Great detective work. On the surface, the charred contacts can be cleaned up, the broken wire a bit more difficult, but both of those leave the question why? It's hard to tell from the photo's but the charring on the relay contacts look like there was a substance (second photo) on there that enabled arcing. Could be I've just never looked at burned contacts through a high res photo. The solder flow on photo 3 is definitely a cold solder joint. The dull finish gives it away. And scoring on the plastic in photo 4 seems to indicate a spectacular failure, if the spherical specs are from melted wire. Looks like there was a current surge through the system.

Did you re-inspect the relay after you cleaned and tried it again? Curious if more arcing showed up.

I would pass these photos on to Chris Coffee as they may indicate at the least a substandard batch of relays.

Hmmm... I see what you mean about the cold solder joint from the old relay. Here's another view of the replacement one they sent. The first time I looked at it I just thought it was a bit messy in there, but now that you point it out, there are tiny balls of metal all over the place close to where the wire was supposed to connect. It's a bit hard to see, but each little dark area that kind of looks like dust is actually a tiny bit of metal:


But... none of them looked like they had settled in to the coils or anywhere else electrically inportant, so I took a chance and soldered a little extension post onto that big blob of solder in the bottom corner - just long enough to span the gap and I reconnected the wire. COOOOOOFFFFEEEEEEEEE!!!!!!!!!!! Mmmm, tastes GREAT!!! The machine has been on for 45 minutes or so now. It is acting absolutely normally! It reached proper temp and started cycling as expected and has been happily clicking along for a little while now.

I will still replace it with the next one Chris Coffee is sending. This will give me the peace of mind of not worrying about what happened to the end of that wire and also that I don't need to trust my so-so skills at soldering.

Thanks again everyone for all the time you've devoted to helping me with this. It's amazing to find just how much people on this list know and are willing to share!

Alex.

I just got the new replacement relay from Chris's. Popped it open and took a look inside - everything looks just right. Stuck it in and I've now had the machine up and running for a couple of hours. Everything's back to normal! Boiler temp, autofill, reservoir... everything! Pulled some shots - I'm now very pleased that this is solved and put to bed.

Thanks everyone! Especially to Eric S, and to Tim in the service dept at Chris Coffee who both took the time to help me understand the inner workings of my espresso machine. When we diagnosed the problem Chris sent parts right away with no hassles. It's great to know that I bought my machine from a dealer that truly stands behind the equipment they sell.

Ok... time to go make myself some coffee now!
Alex.

I agree that the close-up photo of the blackened relays looks like arcing -- this usually happens with inductive loads (i.e. solenoids, motors, other relays), but not resistive loads (heating elements). I'm surprised that this relay would fail like that when switching a high inertia resistive load.

I know that relay contacts can be protected against such loads with snubbers (a small RC circuit across the contacts) or varistors (essentially surge protectors) -- does anyone know of an espresso machine that uses this type of relay protection?