Top 10 HVAC Questions St. Louis Homeowners Ask

1. How often should I have my HVAC system serviced?

Answer: We recommend a twice-yearly maintenance schedule—once in the spring for your air conditioner, and once in the fall for your furnace. In the St. Louis climate, this keeps your system efficient, extends its lifespan, and helps you avoid surprise breakdowns during peak seasons.

2. Why is my AC blowing warm air?

Answer: This is one of the most common service calls we get in summer. Possible causes include:

• Low refrigerant levels (often due to a leak)
• A dirty air filter restricts airflow
• A malfunctioning compressor
• Thermostat set incorrectly

If your system is running but not cooling, it’s best to call for professional diagnostics, especially in humid St. Louis summers when AC is crucial.

3. Is it normal for my HVAC system to make noise?

Answer: Some sound is typical (like the fan running), but clanking, banging, squealing, or buzzing are signs of trouble. Noisy HVAC systems often point to:

• Loose parts
• Motor issues
• A failing blower or capacitor

Don’t ignore it—early attention can prevent major repairs.

4. How can I lower my energy bills without sacrificing comfort?

Answer: Smart ways to boost HVAC efficiency in St. Louis homes include:

• Installing a programmable or smart thermostat
• Changing air filters monthly during high-use seasons
• Sealing ductwork and adding attic insulation
• Scheduling seasonal maintenance

If your system is over 10–15 years old, upgrading to a high SEER unit can significantly reduce cooling costs.

5. Should I repair or replace my old HVAC system?

Answer: If your system is:

• Over 12–15 years old
• Breaking down frequently
• Running inefficiently (high energy bills)
• Using outdated R-22 refrigerant

…it may be more cost-effective to replace rather than repair. We offer free consultations to help you compare options and get the best value.

6. Why is there water leaking around my AC unit?

Answer: Common causes of AC leaks include:

• Clogged condensate drain lines
• Frozen evaporator coils
• Cracked drain pans

Water around your unit can damage flooring or drywall.

7. What’s that smell coming from my vents?

Answer: Strange HVAC smells are a red flag. Here’s what they might mean:

• Musty/mildew: Mold in ducts or drain lines
• Burning: Overheated motor or electrical issue
• Rotten egg: Potential gas leak (turn off system and call immediately)

Indoor air quality is critical, especially if someone in your home has allergies or asthma.

8. How do I know if my ducts have mold?

Answer: If you’re noticing a musty smell, allergy symptoms, or visible black spots near vents, mold could be the culprit. Homes in humid climates, like ours, are especially prone to moisture buildup in the ductwork.

Our team offers professional duct inspections and sanitization services, and we recommend the use of air purifiers or dehumidifiers to help prevent mold from returning.

9. What size HVAC system do I need?

Answer: HVAC sizing isn’t one-size-fits-all. Factors like:

• Square footage
• Insulation levels
• Window orientation
• Ceiling height

…all affect sizing needs. An oversized or undersized system will run inefficiently and cost more in the long term. We perform Manual J load calculations to ensure you get the right fit for your home.

10. Why should I choose a local St. Louis HVAC company, such as Thomas Hoffmann?

Answer: Unlike national chains operating under different names, we’re a locally owned and operated business that’s been serving St. Louis homeowners for decades. Our technicians live here, work here, and genuinely care about the community, so you receive honest advice, fast response times, and personalized service every time.