Nearly all closed-loop hydronic heating and cooling systems are supposed to be filled with water or a mixture of water and antifreeze. The only intentional air in the system is that contained in the expansion tank.
My shop teacher was a wiry man who loved hand tools. We spent a week making a buzzer base. He taught us how to saw, sand and varnish. He introduced me to a Brace & Bit hand drill and went on and on about how this was better than an electric drill. “Can you feel the wood? It’s alive!” he said, and I could.
A second-generation UA member, following in his father Danny’s footsteps into the trade, Nunez began his career in 1984 with Local 460, completing his apprenticeship and spending 18 years in the plumbing and pipefitting industry before being hired by the state of California.