So, I wanted to try out the citric acid dip. I bought two bottles of pure powder and whipped up a mixture (one tablespoon per gallon) in a 5 gallon bucket of hot water. I dipped the heating element in along with its cover. I could see tiny bubbles of action happening, so I kept my eye on it. After about an hour, I removed them. They look good, except for the channel in the cover that is the home for the O ring. That has some stubborn scale in it, so I suppose I'll have to make a stronger mix, or let it soak longer.
The element is clear of debris, but remained black, except for where I scrubbed it lightly to reveal its brassy finish. Maybe I need to soak that more too, as I have flipped through other people's refurb posts and have seen the shiny results.
Next - I think that the entire boiler needs to be dipped, inside and out. So, removing it is fairly daunting, as its got alot of connected tubes. Here's a shot from above-
I removed most of the tubes, all of which came off nicely. Only one required the help of the heat gun. I have two remaining nuts to tackle, one is the drain plug and the other is the main feed to the group, which is the largest nut in the image above, at the bottom center of the frame. Its about 20mm and in a hard to grasp place. I decided to go to bed instead of forcing anything.
I did plug this machine in, I mean, I had to see if it was alive or dead. I flipped the switch to the 1 position for about 1/4 of a second, then off. I did see lights flicker, that was enough for me. I believe that switch position number 2 is for heat, while the number 1 is for the electronics and fill function.
I have inspected the rest of the components. Everything seems to check out with other normal machines of this era. I believe that the motor was frozen, but a gentle twist of a screwdriver on the shaft loosened it up. The same goes for the pump, I believe I will have to remove it and inspect its innards, lube it and hope it works ok.
I'll have to take some images of all of the components, the control board, the stat, the pump/motor, and the rest of the bits. It certainly is engineered well enough. I got one good laugh when I tried to pull off the power switch knob, I realized that it was being held in from behind with a snap ring, some folks call it a C-clip, or retaining ring. I mean, really? It was fully rusted by this point, as they are naked steel. Lucky for me I own more than a few snap ring pliars, as they are common motor parts.
I must admit, when I siphoned out the liquid in the boiler, I didn't have alot of hope, as the water was disgusting. The drain tube also likes to drip out some sludge, and the loosening of the boiler's tubes have leaked out some grimy stuff. But, I'll move ahead, in belief that this machine can be effective, once it gets cleaned up.
My goal is to leave the electrical attached as much as possible. The frame just needs cleaning, not painting. I'll remove the boiler, pump and motor, but leave the rest in and work around them. My weak area is electrics, and so I'd prefer to just leave the harness as is, and clean up the contacts.