remembered a few today.
Tech school teacher was doing energy audits for power co. one system had been put in and customer conplained high power bills. he checked system and was running perfectly, no reason for hi bills.
few mo later he drove by and windows were open. found out they were taking care of mom. she didn't lie a/c, so would open up house after son left, and would close up and restart a/c hour before he came home. no one know what seh was doing until he happened to drive by in day.
Repeated no heat calls from a new install at a Starbucks. New programmable thermostat sub base shorted out every time. The various techs get there but no one can find the cause. This goes on for months. Sometimes problem once in 45 days. Sometimes problem two days in a row.
Get my handy meter out, turn off all the power and connect all the thermostat wires together, connect one lead connection to all the TStat wires and the other to the metal door frame as it represents a good ground. Sit there for maybe two hours as I watch the crews come in and out of the kitchen with the door swinging back and forth.
Getting tired of just sitting there watching the meter and an employee walks through the door and my meter jumps -- just a little.
Ends up the install crew ran the TStat wire behind the metal door frame 2X4's and when the metal door frame was installed they used very long self tapping screws that went far into the wall and sat next to the thermostat wire. With the right combination of a hard door swing and the wire swinging inside of the wall a short would occur.
Repaired the TStat wire and reran it in a different direction including tacking it down and never had a problem since.
Here a story,my Dad told me,RIP DAD!
He was called out to Sbarro's pizzeria on 47st & B'way NYC years ago. Owner told him,not enough cooling & customers are hot. All contractors want is to sell him newer ac eqpt. Btw,he has already added addtl 10tons over last 3 years. He says there is now no more room for addtl.cooling. please help him out.
So Dad goes into an 5'crawl space surrounded by several water/air cooled mini splits.locates main air handler in the back of buildings crawl space. After climbing over ducts,steel to go 60' feet back. It's beginning to get colder,closer he gets.
As soon as he is near,arctic winds are hitting him.
Apparently,Contractors closed ceiling up,before final 8' of duct work was completed.
So he returns with a helper N they clean up coils both sides. Cut and complete the duct run and the owner is ecstatic. Shut down all addtl. Cooling units,no more problems after that. Dad would stop by occasionally and owner treated him like family for years after that.
Years ago the company I worked for replaced a residential heat pump at a local book store. The return was pulled from the drop ceiling. The store was on the first floor of a 3 storey building. When it got below 30* outdoors, the store called and said the heat pump didn't keep it warm. After checking the equipment and finding it working properly, I investigated the ceiling. I found a 3'x5' open wire grille on an exterior wall that pulled in outside air. Blocking the grille solved the problem. Their heating bills went down, too.