Maintaining a cool home in St. Louis, MO, is a top priority when summer humidity hits. Unfortunately, many homeowners follow outdated advice that actually leads to higher bills and more frequent repairs. Understanding the truth behind common cooling myths can save you money and keep your system running longer.
In this guide, we’ll debunk the most persistent AC repair myths and provide the facts you need to maintain a comfortable, energy-efficient home.
9 Common AC Repair Myths Debunked
Don’t let these misconceptions cost you money. Here is the reality behind the most common cooling myths.
1. Myth: Maintenance is only needed when the AC breaks.
The Reality: If you wait until your system stops working, you aren’t doing maintenance, you’re doing a repair. Regular tune-ups are preventative. They allow technicians to catch small issues like worn belts or dirty coils before they cause a total system failure during a St. Louis heatwave.
2. Myth: A bigger AC unit is always better.
The Reality: An oversized unit will “short-cycle,” turning on and off rapidly. This prevents the system from properly dehumidifying your home, leaving you with “sticky” indoor air even if the temperature is low. Proper sizing requires a professional load calculation.
3. Myth: Setting the thermostat lower cools the house faster.
The Reality: Your AC operates at a consistent speed. Cranking the dial down to 60°F won’t make the air come out any colder; it just tells the system to run longer. This adds unnecessary strain to your components and inflates your energy bill.
4. Myth: Closing vents in unused rooms saves energy.
The Reality: HVAC systems are designed for specific airflow “static pressure.” Closing vents disrupts this balance, forcing your blower motor to work harder and potentially causing your coils to freeze. Keep all vents open to ensure proper efficiency.
5. Myth: You should leave the AC on all day to save money.
The Reality: Many believe turning the AC off when they leave uses more energy to cool it back down later. In reality, the Department of Energy suggests raising the temperature by 7–10 degrees when you’re away to save up to 10% on cooling costs.
6. Myth: Refrigerant needs to be “topped off” every year.
The Reality: An AC system is a closed loop. If you are low on refrigerant, you have a leak. “Topping off” without fixing the leak is a temporary fix that can lead to expensive compressor damage.
7. Myth: Ceiling fans lower the temperature of a room.
The Reality: Fans cool people, not rooms. They create a wind-chill effect on your skin but do nothing to lower the actual air temperature. Leaving a fan on in an empty room is just a waste of electricity.
8. Myth: The location of the thermostat doesn’t matter.
The Reality: Placement is crucial. If your thermostat is in a hallway, near a window, or in a kitchen, it may get “false” readings from sunlight or appliances. This causes your AC to run when it doesn’t need to or shut off too early.
9. Myth: DIY repairs are just as effective as professional ones.
The Reality: While changing a filter is a great DIY task, internal repairs involve high-voltage electricity and pressurized refrigerants. Attempting these yourself can lead to safety hazards, voided warranties, or even illegal handling of chemicals.
The True Cost of Neglecting AC Repair
Following these myths often leads to one place: an expensive repair bill. In St. Louis, typical AC repair costs for 2026 reflect the complexity of these systems:
- Diagnostic Fees: $75 – $150
- Capacitor/Contactor Replacement: $150 – $450
- Refrigerant Recharge: $200 – $600
- Blower Motor/Circuit Board: $300 – $900
- Compressor Replacement: $1,200 – $3,500+
Investing in a maintenance plan is the best way to avoid these high costs. Meyer Heating & Air provides plans that include safety inspections and member discounts on any repairs you might need.
Ready to Bust the Myths and Save?
Don’t let cooling misconceptions lead to a sweltering summer. Meyer Heating & Air provides the expert HVAC services in Wildwood or heating and cooling Eureka that you need to stay comfortable. Whether you are looking for heating and cooling services in St. Louis County or a seasonal tune-up, our team ensures your system runs efficiently all season long.
Contact Meyer Heating & Air today to schedule your AC tune-up and start saving on your summer utility bills!
AC Maintenance & Repair FAQs
Most central air conditioners have a lifespan of 10 to 15 years. Regular maintenance is the single most important factor in reaching that 15-year mark.
Look for a company that is family-owned and uses NATE-certified technicians. Meyer Heating & Air is a top-rated choice for homeowners across the St. Louis metro area who value honest diagnostics and upfront pricing.
Yes. A clogged filter restricts airflow, which can cause your evaporator coils to freeze over and potentially damage your compressor, which is one of the most expensive parts to replace.