Solved an annoying electrical issue today

[GreenEnvy22]

My boiler has a 4500w element in it, but I only have 12 gauge wiring in the garage, so can only pull 20 amps. I have two of the round resettable fuses/breakers inside the garage disconnect, one on each leg. This then goes into a breaker panel with a 20amp GFCI breaker for the still.
Anyway, when brewing or distilling, I've been tripping one of the two breakers in the cutoff, at oddly low power, like 11-12 amps. I thought I had some phantom drain somewhere in the garage that was causing it.

Today i shut off all the other breakers in the garage, I ran an extension cord from the house to keep the fridges cold (one food, one beer taps).
So the only breaker turned on was the still.
After 10 minutes or so, again the same resettable fuse tripped. So I grabbed a spare from the house, swapped it out, and voila, now I can run 16amps consistently. Identical models, one must just be defective or worn out.
Happy to have figured this out. Now I'm content with the amount of power available. Heating up 9 gallons from 15C to first drips took less than an hour.


Also got to test how my 55 gallon water drum would do for cooling water. It handed a 9 gallon and then an 8 gallon run back to back, and water was still ok at the end. I wouldn't have wanted to try a third run same day, but at least in the winter, I can do plenty. I have it outside the garage, and punched some cooling lines through the garage wall so I can keep the garage closed while I'm using it.