Putting some info here in case it helps others.

Summary: I have a 10 year old Crossland CC1 V1.0. It recently stopped heating - when I turned it on, I'd get "setup" then "---" flashing, then an error code due to timeout after lack of heating, and the boiler would be cold. This is after 10 years of highly reliable use - little steaming or hot water pulled out, but probably 5,000 double shots and 20,000 hours of on-time. I misdiagnosed the problem as a broken heater coil. The real problem seems to be a glitchy temp sensor, which blew the thermal fuse. I'll replace the temp sensor and update here.

A few details:
1. To take out the boiler, remove only the two screws closest to the LED display screen. These hold the boiler to the group head. The other screws hold the boiler bottom to the boiler top. If you remove them all with boiler in place, you're going to get water everywhere. The boiler can be separated into two parts once it's out.

Measuring across heater coil:

1. These two screws (red) are the heater coil terminals.
2. For a 120V machine which I have, you should measure approx 12 Ohm across them (heater is ~1000W). If the heater is bad, I understand you'll often see 0 resistance (< 2 ohm, for ex.) Best to do this with the wires disconnected (and machine off, of course).

When the CC1 starts up, "Setup" should blink for a few seconds.
Then, you will see "---" flashing. This means the boiler temp is measuring under 150F, but the heater is heating. As it heats, the LED screen will start reading 150F and then increase to 195-205F depending on what you set.

When the heater is heating, if I measure across these terminals with a multimeter -DANGER HIGH VOLTAGE, be careful - I see a fluctuating voltage, the meter reads around 10mV but changes. This is likely because the heater power is PWM controlled at a high speed, with 120V on for short stints. I don't have an oscilloscope to measure more accurately.

I believe the bottom screw is the neutral 120V terminal, the return to the power supply.

The top screw has 3 connections to it. One goes to the pump, one goes to the thermoblock, and one comes from the power supply (likely the hot line, 120V). If I remove the power supply connection while the machine is on, the machine turns off. I assume this is some sort of safety interlock in the power supply or in the controller circuit, which shuts it off if the 120V power circuit is interrupted.

This is what the boiler looks like with the bottom off and the heater coil and steam valve removed.

To remove the heater coil, I needed to remove the steam valve - otherwise you can't turn the brass nuts that hold the heater in place.

To remove the steam valve was difficult. There is a hex copper/brass nut inside the boiler that holds it on. I needed a hefty hex socket wrench with extender and to use a wrench on the steam valve body to exert enough force to get it out. But once it was loose, it came off. I needed some effort to wiggle the steam valve loose.

(The purple lines are where I used a marker to record the position of the steam valve before I removed it, so that I could put it back in the correct angle.)

Now my status, in case anyone has comments:

The heater coil reads 12 ohm resistance and works.
The thermal fuse is blown - 2MOhm across it.
I shorted across the thermal fuse for testing.

Now, when I turn the machine on, I get "---" then the heater heats up. Usually it stops at 205F where I have it set.

However, I just saw the LED switch back to "---", then the boiler started heating up. I opened the steam valve and got more water pressure than usual, suggesting the boiler was over temp and thus over pressure. I power cycled and the machine showed 220F on the front panel (as if the glitch had gone away). Then everything worked fine: the heater stayed off, the boiler settled back down to 205F over 15 minutes.

I'm interpreting this as a glitchy temp sensor, that sometimes cuts out. Then, the CC1 reads a low temp, turns the boiler on max, and -- eventually the thermal fuse will blow. That explains what I saw. The other possibility is the circuit board is glitchy.

I'm going to swap the temp sensor and see if that fixes it.

FYI, shorting the thermal fuse like I have can be very dangerous. I will be sure to leave the steam valve slightly open to vent pressure if I turn the machine on - I don't want to find out what happens if we get thermal runaway.

Will update once I get the other parts.


(And at some point I should just get a new CC1 V2.0 while they are still available. 10 years of service from this thing is pretty impressive.)