Verify licensure and insurance
Missouri requires HVAC contractors to hold appropriate licensure for the work they perform. Ask for the license number and verify it with the city or county where the work will take place.
Insurance is equally important. The contractor should carry general liability and workers compensation coverage. This protects you if a technician is injured on your property or if the work causes damage.
Demand a written estimate
A professional bid should include equipment model numbers, efficiency ratings, capacity, warranty terms, labor scope, and any ductwork or electrical modifications. Vague bids make it impossible to compare apples to apples.
Be cautious of estimates given over the phone without a site visit. Proper equipment selection requires seeing the home, the existing system, and the ductwork.
Check reviews and references
Read recent reviews on multiple platforms and look for patterns. A few negative reviews are normal, but repeated complaints about no-shows, high-pressure sales, or poor communication are red flags.
Ask the contractor for references from recent jobs similar to yours. A reputable company will gladly provide them.
Understand maintenance and warranties
Equipment warranties often require professional registration and annual maintenance to remain valid. Ask whether the contractor offers a maintenance plan and what it includes.
Labor warranties vary. Some contractors warranty their installation work for one year, while others offer longer coverage. Get the warranty terms in writing before signing.
Avoid high-pressure tactics
Be wary of contractors who push a same-day decision with steep discounts, claim the problem is dangerous without evidence, or refuse to provide a written estimate. A trustworthy professional gives you time and information to decide.
Comparing at least two or three bids from STL Home Pros contractors helps you spot outliers and choose the best value, not just the lowest price.
Frequently asked questions
Should I repair or replace my HVAC system?
Consider replacement if the unit is over 15 years old, needs a major repair costing more than half the replacement price, or has become inefficient and unreliable.
How long should an HVAC installation take?
A standard residential replacement usually takes one day. Complex jobs with ductwork modifications may take two to three days.
Do I need a permit for HVAC replacement in St. Louis?
Yes, most municipalities require permits for HVAC replacements. The contractor should pull the permit and schedule inspections as part of the job.
Sources and further reading
The references below informed this guide.
About the author
Nick Cascani is a New York native who has called St. Louis home for the last few years. He believes getting professional home service should be simple and convenient, and he writes these guides to help local homeowners make confident decisions about their HVAC, plumbing, and foundation projects.
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