When there is useful life left
We identify the problem, explain the repair, and discuss cost before approved work begins.
Family owned in O'Fallon, Missouri
O'Fallon HVAC service.
Clear answers, every step.
Repair, replacement, and maintenance for the systems that keep your home comfortable—explained clearly by a local team that treats you like a neighbor.
✓ Costs discussed before work✓ Family owned✓ Clear choices
KirbnJays Heating & CoolingYour Friendly Neighborhood
HVAC Contractor.
HVAC Contractor.
Since 2002Jason's HVAC experience began in the field
Clear optionsUnderstand the choices before deciding
Local ownershipKirby and Jason built the company together
4.9
900+ customer reviewsSee what local homeowners report about their experience
Find the right starting point
What is your system doing?
Choose the closest match. Each page explains what to watch for, what a visit includes, and when it is time to schedule.
Heating, cooling & home comfort
Start with what
your home needs.
Choose the service that best matches the problem. If you are unsure, call us—we will help you choose the right appointment.
AC Repair
Diagnosis and repair for warm air, weak airflow, short cycling, and systems that will not start.
Furnace Repair
Heating-system troubleshooting and repair when your home is cold, noisy, or heating unevenly.
HVAC System Installation
Heating, cooling, or complete HVAC system replacement options planned for the home and installed together when appropriate.
Maintenance
Seasonal system checks that help identify concerns before the hottest or coldest days arrive.
Indoor Air Quality
Installation of whole-home humidifiers and air purifiers for compatible heating and cooling systems.
Ductless Installation
Ductless mini-split installation, plus maintenance and service exclusively for systems installed by KirbnJays.
Water Heaters
Water heater repair, replacement, and installation when hot water becomes unreliable or the equipment begins leaking.
Thermostats
Troubleshooting, replacement, and setup for compatible traditional and smart thermostats.
Repair or replace?
You deserve an explanation—not a sales pitch.
When the numbers point another way
We help you compare system condition, repair history, comfort, efficiency, and replacement choices.
Care beyond the service call
Stay ahead of maintenance.
Start with real first-visit value.
Choose ongoing seasonal care or see the introductory offers available to first-time KirbnJays customers.
Service plansHeating and cooling care that renews with you.
Enroll once for recurring seasonal care, automatic annual renewal, and included maintenance visits tied to your agreement.
Explore service plans →For first-time customers$89 toward an approved repair. Free first maintenance with a new plan.The maintenance offer requires paid, annually renewing memberships for every HVAC system in your home. See both offers and their terms.
View first-time offers →2002Experience that started in the field
Why KirbnJays
Family owned.
Experience since 2002.
Jason Green entered the HVAC trade in 2002, later serving as a service manager before he and Kirby started KirbnJays. The goal was simple: give neighbors the kind of skilled, honest service they would want for their own family.
Discuss the options before work begins
Show respect for your time and home
Stand behind the approved work
Local by design
Based in O'Fallon.
Built for our neighbors.
Our last confirmed service area includes O'Fallon, Lake St. Louis, Wentzville, St. Peters, and St. Charles across 8 ZIP codes. Call to confirm current coverage for your address.
View the service areaHome comfort resources
Useful answers before you book.
Safe homeowner checks and clear decision guidance written to help you understand the next step—not replace a complete diagnosis.
AC Running but Not Cooling? What to Check First
A practical checklist for O'Fallon homeowners when the air conditioner runs but the house stays warm, plus signs that it is time for professional AC repair.
Read the guide →Furnace Running but No Heat? A Safe Homeowner Checklist
Safe checks for O'Fallon homeowners when a furnace runs without producing enough heat, including when to stop and call for service.
Read the guide →Repair or Replace Your HVAC System? A Practical Decision Guide
Compare system condition, repair history, comfort, efficiency, and project cost before deciding whether HVAC repair or replacement makes more sense.
Read the guide →Flexible project financing
Pay over time, rather than all at once.
KirbnJays has partnered with Wisetack to offer flexible financing options. The application takes about a minute, and checking your options does not impact your credit score.
Understand financingSimple by design
- Fast application
- No hidden fees
- Choose from available payment options
*All financing is subject to credit approval. Your terms may vary. Payment options through Wisetack are provided by our lending partners. For example, a $5,500 purchase could cost $253.54 per month for 24 months, based on a 9.9% APR, or $1,833.33 per month for 3 months, based on a 0% APR. Offers range from 0 to 35.9% APR based on amount requested and creditworthiness. Not all merchants and lending partners participate in 0% interest programs. Terms range from 3 to 120 months and may vary based on merchant, lending partner, or transaction size. State interest rate caps may apply. No prepaid finance charges or participation fees. See additional terms at wisetack.com/faqs.
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