My Z1 was reporting overheating errors while heating to mash temperature yesterday. It had already added water to the mash for a rest. The step filter filled nearly to the top. The hop compartments were flooded also.
I wasn’t sure what was happening. After a couple feeble attempts at fixing I gave up and move to my Grainfather.
24 hours later I figured out the source of the problem. The Z1 has a drain tube grommet that connects to a small tube. The tube dips into the wort and sucks it out of a tub (the step filter).
Here is a drain tube grommet.
Here is my bad drain tube grommet close up.
I think maybe a mouse took a bite. I can’t imagine what else might have taken that chunk out of it. With the bad drain tube grommet the drain pump was just sucking air.
Luckily the Z1 ships with a spare grommet. I replaced it and the system seems to function fine.