Served from Hermann, MO
Heating and Cooling in Warren County, MO
Almost half of Warren County's housing has gone up since 2000, which makes heating and cooling in Warren County a different job from the older counties around Hermann. The county held 35,532 people in the 2020 census, and Warrenton, the county seat and largest city, is about 32 minutes from our office.
- 4.7 on Google(15 reviews)
- Serving Hermann since 1998
- Office at 124 E 10th St
Warren County sits north of the Missouri River and belongs to the St. Louis metropolitan area, with rural land giving way to growth from the metro. It runs about 429 square miles, with Route 94 and its vineyards along the south and the I-70 towns across the north. The houses show that growth better than any map does.
Heating and cooling in Warren County homes built since 2000
The median Warren County home was built in 1998, the newest of any county we list. The 2020 to 2024 American Community Survey breaks the recent growth down like this:
- 2000 to 2009: 4,096 housing units
- 2010 to 2019: 2,536 housing units
- 2020 or later: 909 housing units
- Before 1940: 794 units, just 4.9% of the county's 16,161
Newer does not mean trouble-free, and the timing matters. Central AC is commonly quoted at 12 to 17 years, so a system installed with a 2005 house has already had a long run. Owners who bought new are now meeting their first AC replacement decision.
The rules have also moved. New residential AC and heat pumps from January 2025 use A2L refrigerants such as R-454B and R-32, while R-410A is being phased down. Ask for a properly sized heat pump based on a Manual J load calculation, not the tonnage printed on the old unit, because tighter new homes often need less capacity than a builder installed.
Calling from Warren County?
Tell us the town, the symptom and how soon it matters. Our office is open Monday to Friday, 8 AM to 4 PM.
Electric heat leads the Warren County fuel mix
Electricity is the main heating fuel in 71.1% of the county's 13,845 occupied homes, the highest share on our list. Utility gas covers 13.9%, propane 10.3% and wood 3.3%.
So the winter call here is usually a heat pump or air handler, not a gas furnace. Heat pump repair tends to involve defrost boards, contactors and backup heat strips that quietly drive up the bill. Gas and propane are still present, so tell us which you have.
We did not find a source we trust that names every utility in the county, so we will not list them. Service varies by address, so find the company name on your bill before counting on a rebate. Ameren's program, for example, only applies to Ameren customers.
Warrenton, Marthasville and the Route 94 side
Two towns have their own pages, and they are very different jobs.
- Warrenton: about 32 minutes and 26 miles out. The county seat and largest city is a growing I-70 town where newer subdivisions keep heat pumps and air handlers in demand.
- Marthasville: about 37 minutes and 29 miles. This Katy Trail town has older homes, where ductwork and AC maintenance come up more than refrigerant rules.
Marthasville is only 3 miles farther than Warrenton by road but takes 5 more minutes, so do not judge the schedule by mileage alone. Wright City, Truesdale, Foristell and Innsbrook have no pages of their own, so call and we will tell you how your address fits the schedule.
Matching the service to a Warren County house
| Service | Why it fits here |
|---|---|
| AC replacement | The 4,096 units built from 2000 to 2009 are now old enough that an original condenser is at or past the 12 to 17 years usually quoted. |
| Heat pump repair | With 71.1% of occupied homes on electric heat, backup strips running all day during an I-70 cold snap are the first sign something is wrong. |
| Heat pump installation | Newer, tighter subdivisions around Warrenton often need less capacity than a builder installed, which a load calculation will show before you buy. A new build on acreage may suit furnace installation instead. |
| Propane furnace service | Propane heats 10.3% of homes here, usually on acreage beyond the gas lines, and those burners need LP settings and a check of the regulator. |
| Duct repair | The county's 794 pre-1940 units cluster in its older towns, and homes of that age often carry ductwork added long after they were built. |
| AC maintenance | The 909 units built since 2020 are young enough to keep on a schedule now, which leaves a dated service record for the first repair. |
Booking a Warren County visit from Hermann
Call (209) 563-1270 any weekday the office is open, 8 AM to 4 PM. Have the model number from the outdoor unit handy, plus the year your home was built. Original equipment in a newer house can often be matched quickly, which keeps parts planning simple on a 40-minute drive. The quote comes first, and if replacement deserves a look we will show you both numbers.
Calling is fastest
Ask about service in Warren County
Calling gets you an answer sooner, especially if the house is cold or hot right now. If it can wait, send the details and our office will get back to you during business hours.
Smell gas? Do not use this form. Leave the building and call from outside.
What customers say on Google
4.7 on Google(15 reviews)“Hot water heater went out and Brian worked with us to help us find the correct replacement parts, and the repair process. He is knowledgeable, reliable and very responsive. He came out saw that we needed one more possible part and said he wouldn’t charge us labor until the water heater was up and running. We got the right parts he came out to install and had us up and running! We will definitely rely on him again for any future issues with HVAC, water heater, and or plumbing issues! It’s so nice to have hot water again!”
“I can’t say enough good about Brian and his company. They are my go to guy’s. I’ve had them work for me about a half dozen times now. No need to look elsewhere. They are fair and responsive to your needs.”
Good to know
Warren County heating and cooling questions
My Warren County home came with its original heat pump. Should I replace it?
Not on age alone. Have it tested first, then compare the repair quote against replacement. Federal minimums for new split heat pumps are 14.3 SEER2 and 7.5 HSPF2, so a replacement should improve on a tired 2000s unit. New residential systems also use A2L refrigerants, which may change the coil and line set plan.
Why does my all-electric home's bill jump in a Warren County cold snap?
Backup strip heat is the usual reason. A heat pump leans on those electric strips when it cannot keep up, or when a defrost problem or low charge holds it back. If the bill jumps and the house still feels cool, have the system checked rather than raising the thermostat further.
How do I find out if a permit is needed in Warrenton or Wright City?
Call city hall if you are inside city limits, or the county offices in Warrenton if you are not. We could not confirm the county's mechanical rule, so we will not guess at it here. Missouri leaves these rules local as of late 2026. Ask any contractor who pulls the permit.
Heating and cooling help in Warren County
A Hermann company since 1998. Tell us what is going on and we will tell you what happens next.
- 4.7 on Google(15 reviews)
- Serving Hermann since 1998
- Office at 124 E 10th St