Time was, we provided mechanical system inspections for homeowners and realtors. It was a challenge for our clients to schedule all the respective trade experts to show up on time and the cost became prohibitive. The independent certified home inspection industry was born. Instead of coordinating a horde of trade specialists, realtors and prospective homeowners could bring in just one person — the Certified Home Inspector!
As a Master Plumber and HVAC specialist, I’ve been involved when our older son and his wife were looking at homes to purchase to ensure all the PHVAC systems were in good working order. Home inspectors do not test for CO or check beyond does-it-run does-it-heat/cool while going down their extensive list. They don’t have the expertise, for example, to check superheat and subcooling on AC systems.
Now that our youngest son and his wife were looking to buy their first home, Lois & I were anxious to help with checking it top to bottom. However, the only issue was the only opportunity to do so would be while the home inspector was on site. Things I wanted to delve into are considered “invasive” by most home inspection services and not always tolerated.
Lucky happenstance! The inspection was scheduled for a Saturday morning and we would be on vacation. The home was two hours away and upon arrival, everyone arrived within a few minutes of each other: realtor, prospective buyers and the home inspector.
Son Mike introduced me to the home inspector, and explained I was a professional in the mechanical trades. We happened to be standing near the two AC condensers and an antifreeze hose faucet. I noted I wanted to put gauges on to test pressures and the home inspector said that would be fine. Communication is everything and as you’ll discover shortly, he and I were not on the same page!
The home inspection started in the basement mechanical room and storage area. Mike had done lots of research on the home inspectors in the area and had checked with others who had used this inspector. His homework paid off and it soon became apparent this was going to go well. The inspection quickly became a team effort and my input was welcomed. Subtle things he did not catch were pointed out — like an acidic combustion condensate leak on one furnace; the missing traps on the AC coil condensate drains; a missing after-fill tube on a toilet ballcock; and other things my more than four decades of experience helped me pick up on. The undersized 2-gal. thermal expansion tank on a 75-gal. gas-fired water heater and subtle signs the relief valve drips at times, led to a lengthy discussion of Boyle’s Law and why that was the wrong size expansion tank. More to come in a bit regarding the water heater and furnace combustion venting.
I spied lots of yellow PVC-jacketed CSST gas piping attached to the indoor black iron manifold, which was not electrically bonded, and I did not recall seeing a bond-clamp on the exterior gas line. We put that on our list of things to check. It would turn out the gas system was not bonded.
We worked our way through the kitchen, laundry and bathrooms while making notes regarding any defects or deficiencies. When the home inspector moved on to check other things not mechanical, I exited to retrieve my refrigerant gauge set. It was an ideal day to check the two AC systems as we were at outdoor design-day of 95°F conditions. After recording the suction and discharge pressures, ambient air temp, and suction/discharge line temperatures, I knew the superheat and subcooling numbers. Air split across the condenser was good too.
Mike suddenly appeared to tell me the home inspector was having a fit about my hooking up refrigerant gauges — too invasive and not allowed. When we first met and mention putting gauges on, he thought I meant at the hose bib to check water pressure! Given that the air split temperatures (non-invasive) across the second condenser and indoor supply/return ducts were virtually identical to the first AC system, it was a relatively safe assumption the second system was fine too.
Combustion venting issue! While checking out the power-vented Bradford White water heater, I noticed the PVC pipe marking was SCH 40 COEX CELLULAR CORE PVC-DWV PIPE. Same for both of the furnace combustion exhaust vents. What’s good for the geese isn’t necessarily good for the gander. While both of the furnaces’ cellular core (also called foam core) is legal and code compliant as was the water heater’s PVC exhaust — at the time it was installed — cellular core was outlawed for water heater exhaust venting in 2016. Bradford White revised their manuals and made the switch to solid core PVC in 2015.
When his report was submitted, I was pleased to see every single issue I had raised was in his report.
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