The Human Diagnostic
Looking for honest stories about people, not product reviews? You're in the right place.
The Human Diagnostic isn't a how-to HVAC podcast. It's what a 45-year Master Technician notices about people after 90,000 service calls across gas plants, oil rigs, hospital preservation systems, high-rises, feedlots, walk-in freezers, and residential homes all over Central Oklahoma.
Hosted by Dave Hartzell, each episode tells a real story from a real service call. Sometimes he's driving to the job and predicting what he's about to walk into. Sometimes he just left and he's still working through what he saw. Either way, the story turns out to be about more than HVAC.
Topics you'll hear across the season:
✅ The customer nobody wanted to take, and what changed when someone finally did
✅ Why the person researching their broken AC at midnight isn't being difficult, they're scared
✅ What 45 years of walk-ins, weddings, funerals, and broken water heaters teaches you about anxiety
✅ The tech who can fix anything but can't explain it, and why the customer doesn't trust him
✅ The review you can't place, the moment you never forget, the call that changed how you work
✅ What gets lost when we treat people like tickets, and what gets found when we don't
Whether you fix things for a living, manage people who do, or just like good stories from someone who has been everywhere and met everybody, The Human Diagnostic gives you the part of the job that never shows up in an invoice.
📍 Proudly based in Kingfisher and serving Edmond, Guthrie, Yukon, Mustang, Piedmont, Logan County, Canadian County, Blaine County, Major County, Garfield County, and the greater Oklahoma City metro area. Hartzell's Heat & Air blends old-school integrity with cutting-edge technology, from digital diagnostics to smart-home HVAC integrations.
Connect with Hartzell's Heat & Air:
📲 Facebook: facebook.com/hartzellsheatair
🐦 X (Twitter): x.com/HartzellsHVAC
▶️ YouTube: youtube.com/@hartzellsheatair6003
💼 LinkedIn: linkedin.com/in/dave-hartzell-7a687515
📧 Contact Us: office@hartzellsheatair.com
Every call is a story. Every story is a person.
🔔 Subscribe to The Human Diagnostic and ride along.
📞 Need HVAC help in Central Oklahoma? Call (405) 375-4822
🌐 hartzellsheatair.com
The Human Diagnostic
Latest Episodes
He Was Certain He Was The Reasonable One About The Heat Pump
He told me the last company had been working him, and about nine seconds later he told me exactly what was wrong with his air conditioner and how he knew. Late August, one of those weeks where it never gets below eighty at night and the ...
The Woman Who Couldn't Believe the Repair Held
By the time I pulled out of the shop she had called three times, and nothing about her job had changed since the first one. First full week of July, heat index sitting around 105 by early afternoon. Two story house in one of the newer ad...
The Repair He Feared Less Because He Could See It Coming
He picked the more expensive repair and looked relieved doing it. Late August, a brick ranch on the edge of town, the kind built in the nineties with the condenser tucked up against the north wall where nobody ever hears it run. Retired ...
The Worry She Was Certain Showed While the Heat Pump Ran
She had been terrified about the money for two hours and I had no idea, because she thought it was written on her face. Early spring, a rent house out toward the county line, tenant not owner, which changes the whole shape of a call. You...
The Repair She Put Off Because Bad Luck Happens To Others
He agreed with every word I said about the failure, and then explained why it would not happen to him. Composite call. This is four or five conversations stacked into one, because the pattern is the point and I am not putting a real cust...