| Business | Phone |
| All Climate Heating & Air Cond Po Box 95, O Fallon 63366 | (636) 978-1283 |
| Baden Mechanical 6505 Sprucefield Dr, O Fallon 63368 | (636) 272-1057 |
| Brauer Supply 3355 E Terra Ln, O Fallon 63366 | (636) 970-6778 |
| Rogers Comfort Systems 127 S Main St, O Fallon 63366 | (636) 978-3314 |
| Sauer Heating & Cooling Inc 11 Bramblett Holw, O Fallon 63366 | (636) 294-2777 |
| Qualified Heating & Cooling 410 Trent Park Dr, O Fallon 63368 | (314) 921-0157 |
| One Hour Air Conditioning 1208 Bramblett Rd, O Fallon 63366 | (636) 281-8686 |
| Myers Heating & Air Cond 10 Country Life Dr, O Fallon 63366 | (636) 281-4689 |
| J & E Heating & Cooling Co 30 W Industrial Dr, O Fallon 63366 | (636) 441-4484 |
| Grand Oaks Heating & Air Cond 1208 Bramblett Rd, O Fallon 63366 | (636) 926-2007 |