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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
The Thermostat Problem That Was Really a Cold Chair
A woman in Okarche told me on the phone that her whole house was cold. She wanted me out the same day. I asked her where in the house she had measured. She had not measured anywhere. She just knew. I drove out. I put my hand on the suppl...
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The Uniform of Calm I Put On for a Furnace Repair
A customer once told me I was the calmest man she had ever met. I thanked her. I did not tell her the truth, which was that I had been up since four that morning with a sick dog and a bad night, and the calm she was admiring was something I had...
The Air Conditioner Repair Where She Fed Me Lunch
Her air conditioner had been dead for two days in an Oklahoma August, and the first thing she did when I walked in was hand me lunch. Not water. Not a chair. A sandwich, made before I had my tools out of the truck. The house was hot enou...
The Broken Compressor She Swore She Predicted
A woman in Dover told me, right after I condemned her compressor, that she had known all along it was going to go out this summer. She said she had felt it. She said the unit had been telling her since spring. I asked her, gently, what t...
The Furnace Repair She Remembered Wrong On Purpose
A woman called me a year after a job to thank me for a furnace repair I barely remembered. It had been a long one. Her furnace quit on the coldest week of the winter, and I was at her house most of the day, pulling the blower, driving back to t...