HVAC Service in St. Charles, IL
MMDS has been fixing and replacing furnaces, air conditioners, boilers and heat pumps across the Chicago suburbs since 2003. Our Crystal Lake location is about 22 miles away. When you call, you talk to the people who do the work, and most St. Charles service calls are seen the same or next day.
Hours: Monday–Friday, 7:30am–5:00pm. Emergencies: we take calls 24/7.
What We See in St. Charles Homes
St. Charles has historic homes near the river and many newer subdivisions. The city runs its own electric utility, so ComEd heat pump discounts don’t apply here. A few things come up often:
- Builder-grade equipment at the end of its life. Many homes here still have the original furnace and AC from when the house was built. At 20+ years, replacement usually beats repeated repairs.
- Hot upstairs, cold basement. Two-story homes often fight uneven temperatures. Sometimes the fix is balancing or zoning, not a bigger system. See our air balancing service.
- ACs still running R-22. Older ACs that use R-22 refrigerant are getting expensive to recharge. If yours is leaking, replacement usually makes more sense than repeated refills.
HVAC Services in St. Charles
- Cold-climate heat pump installation, including dual-fuel setups that use the heat pump most of the year and your furnace below about 35°F
- Furnace and boiler replacement
- Heating repair
- AC installation and replacement and AC repair
- Maintenance plans and tune-ups
- Indoor air quality, thermostats and duct cleaning
Replacement Costs in St. Charles
Every house is different, but here are honest ranges: AC about $4,000–$8,000; heat pump about $6,000–$10,000 before rebates; furnace about $4,000–$10,000 depending on size, efficiency, brand and location. We install Trane, Carrier, Bosch, Midea, LG, Gree and Goodman, and all equipment comes with a 10-year factory parts warranty, with extended labor coverage included or available depending on the package. In our climate, paying extra for anything above about 17 SEER2 rarely pays back.
Rebates and Utilities in St. Charles
St. Charles runs its own municipal electric utility, so ComEd’s heat pump discounts don’t apply here. Ask us about current St. Charles utility programs before you buy. Gas service is through Nicor Gas. The federal 25C tax credit for heat pumps and furnaces ended for equipment installed after December 31, 2025, so if someone is still quoting it to you, ask questions.
Maintenance
Our one-time tune-up is $150 and includes a real cleaning of your equipment. An inspection is $79. Maintenance plans start at $15/month and cover an AC visit before cooling season and a furnace visit before heating season.
St. Charles HVAC FAQ
How fast can you get to St. Charles?
Our Crystal Lake location is about 22 miles away. Most service calls are same or next day, and emergencies are answered 24/7.
Are there heat pump rebates in St. Charles?
St. Charles has its own electric utility, so ComEd discounts don’t apply. We’ll help you check what the city offers before you decide.
Should I replace my furnace and AC at the same time?
Not always. If your AC is old and your furnace is in good shape, a heat pump can replace the AC and take over most of your heating. We’ll look at both and tell you what makes sense.
Nearby Areas We Serve
We also work in Geneva, Batavia, South Elgin, West Chicago, Bartlett, Elgin. See the full service area.
Schedule Service in St. Charles
Book online or contact us and we’ll get you on the schedule.