❄️ Official Rankings
10 Best HVAC in O'Fallon, MO (September 2026)
We compared 10 hvac serving O'Fallon and Saint Charles County, Missouri, and ranked the top providers by verified reviews, ratings, and local reputation — 6,720 customer reviews in all.
The 10 listed below hold an average rating of 4.9 out of 5, led by Stay Cool Climate Control. Updated for September 2026.
- HVAC ranked
- 10
- Average rating
- 4.9★
- Reviews analyzed
- 6,720
- Area codes
- 636, 314
⭐ 5.0 · 1144 reviews
407 Sonderen St, O'Fallon, MO 63366
⭐ 5.0 · 877 reviews
103 Church St #20, O'Fallon, MO 63366
⭐ 4.9 · 1519 reviews
1520 Kemmar Ct, O'Fallon, MO 63366
⭐ 4.9 · 937 reviews
406 E Wabash St, O'Fallon, MO 63366
⭐ 4.9 · 870 reviews
1613 E Terra Ln, O'Fallon, MO 63366
⭐ 4.9 · 725 reviews
110 W Pitman St, O'Fallon, MO 63366
⭐ 4.9 · 366 reviews
674 Whispering Willow Dr, O'Fallon, MO 63366
⭐ 5.0 · 48 reviews
113 Triad Center W, O'Fallon, MO 63366
⭐ 4.8 · 140 reviews
3120 Industrial Park Pl W Dr, St Peters, MO 63376