15+ years • 6,500+ jobs completed • 1,500+ Oklahoma homes served
I am Dave Hartzell. I have been working on heating and air conditioning in Oklahoma for 47 years. I opened Hartzell’s Heat & Air in Kingfisher around 2011. Below is every credential I hold and every manufacturer that has named me a top-tier dealer. Each one took years and ongoing training. None of them are paid placements.
4.8 stars / 300+ Google reviews. Master HVAC. NATE certified. Family owned in Kingfisher.
Common questions about HVAC credentials
How long has Dave Hartzell been doing HVAC?
47 years total HVAC experience. I started at 18 and opened Hartzell’s Heat & Air around 2011. 15+ years in business under my own name in Kingfisher.
What is the difference between a Master HVAC license and a regular license?
Oklahoma Master is the highest residential/light-commercial level. It covers design, installation, service, and supervision of journeymen. Many contractors hold only a journeyman or contractor license. I hold Master.
Why does NATE Certification matter for HVAC repair?
NATE is independent. Manufacturers train you on their gear, but NATE tests you on real-world diagnostics across brands. It means the tech in your house has been measured against a national standard, not a sales pitch.
Do I need an IGSHPA-accredited installer for geothermal?
Yes for warranty registration on most geothermal equipment. Loop design, pipe fusion, and proper charge all sit outside what a standard HVAC license covers. IGSHPA proves the installer is trained on the ground side, not just the heat pump.
What does Mitsubishi Diamond Dealer get me as a customer?
12-year compressor warranty on Diamond-tier installations, instead of the standard 5-7. Factory tech support direct line for diagnostic help on a stubborn fault. Priority on equipment availability.
Is BBB accreditation worth checking?
It is one data point. 11 years accredited at A+ means the complaint trail is public and the resolution rate stayed clean for over a decade. Pair it with Google reviews (4.8 stars / 300+ reviews) and you have a real picture.
Ready to work with a Master HVAC tech?
Call (405) 375-4822 or book online. Free estimates on new installs. $99 dispatch, $111 diagnostic, part of the $210 flat repair-call price. The tech gives a written repair estimate before repair work starts.
Related
- See the full service list: What Hartzell’s does (and doesn’t) do