I once kicked an "experienced" boiler tech out of my parent's house and bitched loud and long to the company's owner (I used to date his daughter).
Mom and Dad had an oil-fired steam boiler. He came around for the yearly inspection/cleaning and was doing his thing when I noticed him messing with the pressuretrol.
Me: "Uhm, why are you moving the limits?"
Him: "They're too low. I'm setting them where they should be." (uh oh, Danger, Will Robinson!)
Me: "OK...... Where SHOULD they be?"
Him: "Well, to heat a house this big, you need at least 10 psig and a differential of 2 (8 psig, which is FAR too high for a home heating system). You probably aren't getting any heat on the third floor because the steam pressure is too low." (We didn't get heat on the third floor because the heating system was never extended to the third floor when it was installed around 1895)
Me: "Uhmmmmm..... Why?"
Him: "Because it's a big house, it will get the steam up faster. If you set the pressure higher you save money and don't need main vents." (My head about popped at that point, and I'm pretty sure that the veins on my forehead were throbbing and kicking off more heat than the boiler).
What followed was a rather lengthy discussion of the properties of steam and home heating systems.
Things like home heating systems are called vapor steam systems, 1 pound psig head will drive a column of steam something like 3,500 feet up a vertical pipe, etc., none of which he knew.
I finally set the pressuretrol back to 1.5 and .5, thanked him for the cleaning, and told him I'd be talking to his boss about his theories on steam heat.
My Dad wasn't very happy, my Grandfather wasn't very happy (he was a mechanical engineer who, among other things, was responsible for the boilers at the American Viscose plant in Lewistown, Pennsylvania, for years), and the owner of the heating company wasn't too happy, either. We got that cleaning for free...
He also offered me a job working with them on their residential steam heating systems for the summer.
I found more than a few pressuretrols that were badly misset and more than a few main vents that had ceased functioning sometime during the Roosevelt administration. I made my money that summer and save a lot of people in my town money on their heating bills.
