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✓ Work guaranteed
KirbnJays Heating & CoolingYour Friendly Neighborhood
HVAC Contractor.
HVAC Contractor.
Serving O'Fallonand nearby communities
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.
0102030405060708
Explore all services AC Repair
Diagnosis and repair for warm air, weak airflow, short cycling, and systems that will not start.
AC Installation
Thoughtful replacement options and professional installation for dependable summer comfort.
Furnace Repair
Heating-system troubleshooting and repair when your home is cold, noisy, or heating unevenly.
Heating Installation
Replacement planning and installation for furnaces and compatible home-heating systems.
Maintenance
Seasonal system checks that help identify concerns before the hottest or coldest days arrive.
Ductless Installation
Ductless mini-split installation, plus maintenance and service exclusively for systems installed by KirbnJays.
Water Heaters
Repair and replacement guidance 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.
2002Experience that started in the field
Why KirbnJays
Family owned.
Field experienced.
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.
01Discuss the options before work begins
02Show respect for your time and home
03Stand behind the approved work
Local by design
Based in O'Fallon.
Built for our neighbors.
KirbnJays serves O'Fallon, Lake St. Louis, Wentzville, St. Peters, St. Charles, and select nearby communities. Confirm your city and ZIP code on the service-area page.
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.
01
View all homeowner resources 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 →02Furnace 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 →03Repair 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
Comfort shouldn't have to wait.
Explore available monthly payment options through Wisetack for qualifying repair and replacement projects.
Understand financingSimple by design
- Fast application
- No hidden fees
- Choose from available payment options
Need help with your system?