Hartzell’s Heat & Air | The 7 Most Common HVAC Repairs in Central Oklahoma

The most common HVAC repair in central Oklahoma is an AC that quits cooling. By a mile.

People ask me all the time what breaks the most. I do not have to guess. I went back through nearly a decade of my own work orders here in central Oklahoma and counted what actually failed.

I pulled 3,169 real jobs I ran from 2016 through early 2026. Of those, 1,064 were repair calls. This is my own service history, not a survey or a national average. Here are the seven repairs I run most, in order, with the real counts behind them.

1. AC not cooling (about 356 calls, roughly a third of all repairs)

This is the no-cooling call: the system runs but the house keeps climbing, or the unit will not kick on at all. I combine my general AC calls and my flat no-cooling calls here, 356 in total, and it dwarfs everything else at about one in three repairs. In Oklahoma it happens because a unit sits idle through winter and spring, then the first long June run finds the weak part. Get a tune-up in May and most of these never become a 100-degree emergency.

2. Condensate and drain clogs (67 calls)

Your AC pulls humidity out of the air and that water has to drain somewhere. In our humidity the drain line grows algae and sludge, plugs up, and the safety switch shuts the whole system down, usually on the hottest day. Here is the honest part: this is the cheapest failure on the list to prevent. I flush and treat the drain on every tune-up, so a $138 plan visit stops a $99 dispatch call in July. Few repairs pay you back like this one.

3. Geothermal and loop work (61 calls)

I install and service a lot of geothermal around Kingfisher, so loop pressure, flow centers, and pump issues show up more on my list than they would for a shop that does not touch geo. Most of it is loop fluid or circulator related, not the heat pump itself. If you run geothermal, a yearly check of loop pressure catches small drops before they cost you capacity in the dead of summer or winter.

4. Thermostat issues (60 calls)

A surprising number of no-heat and no-cooling calls trace back to the thermostat, not the equipment outside. Dead batteries, a tripped float switch wired through it, a bad smart-stat setup, or just bad wiring at the subbase. It is one of the cheaper things I fix, and I will always tell you straight when the box on the wall is the problem and not your compressor.

5. Refrigerant and leaks (48 calls)

A system low on refrigerant is leaking, plain and simple, because a sealed system does not use it up. Oklahoma heat and age work the coils and joints until a slow leak shows. I find the leak and fix it rather than just topping you off year after year, which is throwing money at a hole. With older R-22 systems I will also be honest about when a leak means it is time to talk replacement.

6. Blower and fan motors (47 calls)

The indoor blower and the outdoor fan motor both run hard through our long cooling season, and heat plus dust plus run hours wear out bearings and windings. When a fan motor quits, the system can overheat and shut down or freeze up. Catching a motor that is pulling high amps on a tune-up lets me plan the swap instead of you losing cooling on a Friday in August.

7. Capacitors (42 calls)

The capacitor is the cheap little part that gives your compressor and fan the jolt to start. Oklahoma heat is brutal on them, and a weak one is the classic reason a unit hums but will not start on the first hot day. It is an inexpensive part and a fast fix, and a tune-up will catch a capacitor that is reading low before it strands you.

The honest takeaway

Look at this list and a pattern jumps out: most of the top failures are catchable. Drain clogs, weak capacitors, low refrigerant, tired motors, and loop pressure all show up on a tune-up before they leave you without heat or cooling. That is why I push maintenance, not because it pads a ticket, but because four of my top seven repairs are cheaper to prevent than to fix on the worst day of the year.

Frequently asked questions

What is the most common HVAC repair in central Oklahoma?

An AC that quits cooling. Across 1,064 real repair calls I logged from 2016 to 2026, no-cooling and general AC failures came to about 356 calls, roughly a third of everything I fix. The first long heat of June is what exposes the weak part.

What is the cheapest HVAC problem to prevent?

A clogged condensate drain. It was my number two repair at 67 calls, and I flush and treat the drain line on every tune-up. A $138 maintenance visit stops a backed-up line from shutting your system down on a 100-degree day.

Why does my AC hum but not start?

Usually a weak capacitor. It is a cheap part that gives the compressor and fan the jolt to start, and Oklahoma heat wears them out. It was 42 of my repair calls and one of the fastest, least expensive things I fix.

Do you work on geothermal systems?

Yes. Geothermal and loop work was 61 of my repair calls, and I am IGSHPA accredited. Most geo repairs are loop pressure or circulator pump issues, not the heat pump itself, and a yearly loop check catches small drops early.

How do you know this and not just guess?

This is my own work order history, 3,169 jobs and 1,064 repair calls over nearly nine years in central Oklahoma, not a national stat. I am Dave Hartzell, Master HVAC, 45 years in the trade, 4.8 stars across 279 reviews.