Damned
Damned engineers, LOL
Carrier did the same kinda jazz back in the 70 on residential air conditioners, Had this 6x8 inch pc board in the outdoor AC (smart, huh? pc boards that live outside....)
nightmare to diagnose and fix, and one day on a 10-15 year old unit that the board was bad, quoted about 800 dollars for the board, and listening to a customer GO OFF about highway robbery and such. I sat staring at it for a few minutes
and said let me stare at the process here....I have an idea...He left and after looking at it and wandering thru the schematic, I realized that none of it was truly needed and all this needs is 24 volt source to energize the contactor. and what was once a five minute time delay on the board is actually handle by most digital thermostats now days.
I stuck in a contactor after riping out the board and wiring, hooked up yellow and common to the contactor and poof, it take off running. The guy comes out with a WTF look on his face and looks at the board on the grass and I looked back at him and said.
"damned engineers". I explained what was going on and what it really needed and then he told me that while inside, he called a few places and was quoted even higher prices and a refusal to work on it. he paid me 1/4 the original price and was happy as hell. And them with a chuckle he told me he was an electrical engineer......