HVAC Company Serving St. Peters, MO

Martin-Jetco Heating and Air Conditioning has worked across St. Charles County since 1964 and remains family-owned. Our licensed, NATE-certified technicians evaluate the full system before recommending anything.

Need HVAC Service Today?

• Same-Day Appointments Available
• Emergency Service 24/7
• Licensed, NATE-Certified Technicians
• Family-Owned Since 1964
• 1,000+ Five-Star Google Reviews
• Financing Available

If your St. Peters home has uneven temperatures, rising repair costs, or a system that cannot keep up we can take a closer look. Call (636) 205-1631 today or message us online.

Heating & Cooling Services for St. Peters Homes & Businesses

• AC Repair
• AC Installation
• AC Replacement
• Furnace Repair
• Furnace Installation
• Furnace Replacement
• Heat Pump Services
• Ductless Mini-Splits
• Indoor Air Quality
• HVAC Maintenance
• Emergency HVAC Service
• Boilers, geothermal systems, and commercial heating and cooling

Martin-Jetco Heating and Air Conditioning carries all major HVAC brands, including York, Goodman, Daikin, Carrier, and Trane, which lets our team offer replacements across a range of efficiency levels and price points. Financing is available for qualifying projects.

How Much Does HVAC Replacement Cost in St. Peters?

HVAC replacement falls into two general price ranges:

• AC replacement with evaporator coil: approximately $5,500 to $9,200 
• Complete HVAC system replacement: approximately $8,450 to $22,990 or more 

Where your project lands depends on the home, the existing system, and the equipment you choose. The biggest cost factors usually include:

• Home size and required system tonnage 
• Ductwork condition, including sealing, resizing, or replacement needs 
• Standard equipment versus high-efficiency variable-speed equipment 
• Zoning for two-story homes, multi-level layouts, or finished lower levels 
• Electrical or code updates needed before installation 
• Indoor air quality upgrades added to the system 
• Equipment access in finished basements, closets, or tight mechanical spaces 

An in-home evaluation gives Martin-Jetco Heating and Air Conditioning the details needed to price the work accurately. Our team looks at the equipment, ductwork, airflow, access, and comfort concerns before giving you a replacement estimate based on what your home actually needs. Request an estimate online or call (636) 205-1631.

Typical HVAC Repair Costs in St. Peters

After years of service calls across St. Peters, Martin-Jetco Heating and Air Conditioning knows which repairs homeowners ask about most often and what those repairs tend to cost once the problem is diagnosed. The exact number depends on the part, system age, equipment condition, and accessibility, but these working ranges can help you understand the scale of the repair before deciding what makes sense:

• Capacitor: $150 to $450 
• Thermostat: $100 to $600 
• Ignitor replacement: $180 to $350 
• Flame sensor: $180 to $340 
• Furnace capacitor: $150 to $350 
• Blower motor: $500 to $1,400+ 
• Evaporator coil: $600 to $2,000 
• Control board: $700 to $1,650 
• Heat exchanger: $2,000 to $4,000 
• Compressor-related failures: well over $1,000

After diagnosing the system, our technician gives you the exact cost and compares it against AC replacement or furnace replacement before recommending a path forward. Call (636) 205-1631 or message us online to schedule an in-house evaluation.

When Heating or Cooling Can’t Wait, Call (636) 205-1631

Some HVAC problems can wait for the next open appointment. Others need attention the same day. Based on the emergency calls Martin-Jetco Heating and Air Conditioning handles in St. Peters, these are the situations worth calling about right away:

• The heat is out. January nights in St. Peters often drop into the 20s, and a home can get uncomfortable fast. 
• The AC has quit. On a hot Missouri day, indoor temperatures can climb quickly, especially in two-story homes or homes with limited airflow. 
• The system is running, but no air is moving. A blower issue or blocked airflow can strain the equipment without heating or cooling the home. 
• You smell burning or hear a new noise. Electrical smells, grinding, scraping, or banging should be checked before the system keeps running. 
• A business system is down. Medical offices, retail spaces, and commercial properties need fast diagnosis when comfort affects daily operations. 

Emergency HVAC service is available around the clock, including evenings, weekends, and holidays. A technician diagnoses the problem on site, explains what failed, and gives you a firm repair cost before work is authorized. Many repairs can be completed during the same visit, and repairs that require parts are scheduled as quickly as availability allows.

Lower the Cost Before You Replace Your HVAC System

A new HVAC system can be expensive, but Martin-Jetco Heating and Air Conditioning helps homeowners and businesses find ways to reduce the upfront cost, lower the final total, or spread payments out.

During your in-home evaluation, our technicians review options that may apply to your project, including:

• Financing for qualifying projects. Financing can turn a large replacement cost into a fixed monthly payment, which may help when replacement comes sooner than expected. 
• Utility rebates. Eligible higher-efficiency equipment may qualify for rebates, and our team files the rebate paperwork on your behalf at installation. 
• Federal energy-efficiency tax credits. Qualifying heat pumps and high-efficiency furnaces may be eligible for federal tax credits, depending on the equipment and current tax-year rules. 
• Seasonal promotions. Current offers may be available when you call or schedule your estimate, and our team will include any applicable savings in your options. 

You see the equipment cost, financing options, rebates, credits, and available promotions together, so you can compare the real cost before deciding.

Which St. Peters Home Type Matches Your HVAC Challenge?

What HVAC Issues Are Common in Older St. Peters Homes?

One of the most common things our technicians see in St. Peters is a homeowner replacing a furnace while still relying on original builder-installed ductwork from the late 1980s. Before recommending new equipment, we evaluate airflow throughout the home because balancing and duct improvements often make as much difference as the equipment itself.

St. Peters was built almost entirely during the suburban boom of the 1980s and 1990s, and that specific construction era created a predictable set of HVAC patterns:

• Original builder-grade ductwork still in place. Subdivisions like Steeplechase, Heritage, Ohmes Farm, Spencer Creek, Woodstone, Belleau Creek, and Hi Point Acres represent some of the most common housing in St. Peters. Homes from this era were typically built with ductwork sized to meet code rather than to optimize comfort over decades, and many of these systems have never been sealed, balanced, or evaluated since original installation.
• Second equipment cycle on first-generation ducts. Many St. Peters homeowners have already replaced their furnace or AC once. The new equipment went in, but the ductwork stayed the same. The result is a high-efficiency system that cannot perform at its rated efficiency because the distribution system was never updated to match.
• Two-story colonials and open floor plans with uneven temperatures. The dominant floor plan in many subdivisions is a two-story colonial with an open main level. These layouts accumulate heat upstairs in summer and leave main floors overcooled. The ductwork was rarely balanced for the actual floor plan.
• Finished basements, sunrooms, and growing-family additions. St. Peters homeowners have been finishing lower levels, adding sunrooms, and converting spaces for decades. None of those additions were part of the original duct plan.
• Return air issues throughout. Builder-grade homes from this era often have undersized return air systems. The blower works against higher static pressure than it was designed for, reducing airflow, straining components, and limiting what a new system can actually deliver.

If any of this sounds like your home, call (636) 205-1631 or schedule a diagnostic visit.

Why Does My Upstairs Bedroom Stay Hot?

In the subdivisions off Kisker Road, McClay Road, and Veterans Memorial Parkway, upper-level heat accumulation in summer is one of the most consistent complaints our technicians hear. Here is what is happening:

• The stack effect. Heat rises naturally, and in a two-story home where the upper level is connected to the main floor by a stairwell, warm air accumulates upstairs regardless of the thermostat setting below. The main floor cools quickly; the upper level stays warm.
• Supply ductwork was never balanced for the upper floor. Builder-grade duct runs in 1980s and 1990s two-story homes were sized to meet code minimums, not to deliver equal supply air to each level. The main floor gets adequate airflow; the upper floor gets whatever is left over after losses through undersized or leaky runs.
• Undersized return air on the upper level. Without adequate return air on the upper floor, the system cannot pull warm air back down to the equipment efficiently. The upper floor stays warm and the main floor gets overcooled as the system tries to compensate.
• Solar gain and attic temperatures. Bedrooms directly below the roofline absorb radiant heat from both the sun and the attic space above. Attic temperatures in Missouri can exceed 140°F in summer, and that heat transfers through the ceiling into the rooms below, putting constant additional load on whatever supply air reaches them.

Our technicians measure static pressure and airflow at every register before recommending a fix. The solution is often less expensive than a full replacement.

Why Is My St. Peters Basement Always Too Hot or Cold?

Walkout lower levels and finished basements are a fixture of St. Peters homes, and they are also one of the most common comfort complaints our technicians hear. The reason is straightforward: the original duct system was never designed to condition that space.

Whether the lower level became a movie room, bedroom, home office, or exercise room, it relies on whatever conditioned air drifts down from the main floor. That is not enough for consistent comfort.

Solutions depend on the space and what the existing system can support:

• Duct extensions connect the lower level to the existing system where layout and capacity allow
• Air balancing redirects supply air to underserved areas when the system has available capacity
• Zoning systems give the lower level its own thermostat, independent of what the main floor is doing
• Ductless mini-splits provide independent heating and cooling without relying on the main system, the most practical choice when duct extension is not feasible

Where We Serve in St. Peters

Martin-Jetco Heating and Air Conditioning serves homeowners and businesses throughout St. Peters and the 63376 zip code, along with nearby St. Charles County communities.

The team serves established and newer residential areas across St. Peters, including neighborhoods such as Steeplechase, Hi Point Acres, Heritage, Cottages at Wedgewood, Village Point, Green Forest Estates, Ohmes Farm, Spencer Creek, Woodstone, and Belleau Creek. Service is also available for homes along and near Mexico Road, Willott Road, Mid Rivers Mall Drive, Jungermann Road, Kisker Road, McClay Road, Spencer Road, Veterans Memorial Parkway, Cottleville Parkway, and the Highway 370 and Highway 94 corridors.

Local service areas include homes and businesses near Barnes-Jewish St. Peters Hospital, the St. Peters Rec-Plex, 370 Lakeside Park, Laurel Park, City Centre, Mid Rivers Mall, the Spencer Road Branch Library, the St. Peters Cultural Arts Centre, St. Peters Golf Club, and Cave Springs.

Families in the Francis Howell, Fort Zumwalt, and City of St. Charles school districts can reach Martin-Jetco Heating and Air Conditioning for HVAC service throughout the St. Peters area, including those connected to Francis Howell North High School, Fort Zumwalt East High School, Fort Zumwalt South High School, Barnwell Middle School, Hollenbeck Middle School, Fairmount Elementary, Hawthorn Elementary, Lewis and Clark Elementary, and Mid Rivers Elementary.

Keeping Your System in Peak Condition Ahead of the Season

The Martin-Jetco Heating and Air Conditioning Home Comfort Agreement keeps maintenance on the calendar before peak cooling and heating demand. Spring and fall inspections give technicians a chance to catch small issues before they turn into mid-season breakdowns.

Membership includes:

• Pre-season maintenance before cooling and heating demand each year 
• Complete safety and performance inspection at each visit 
• 20% off parts and labor on repairs between visits 
• No premium for after-hours or weekend calls 
• Priority scheduling when an unplanned issue comes up 
• Reduced diagnostic fee during regular business hours 
• Documented HVAC maintenance records for most manufacturer warranty requirements 

Call (636) 205-1631 to add the Home Comfort Agreement to your next service visit.

A Local HVAC Team You Can Feel Comfortable Calling

Martin-Jetco Heating and Air Conditioning has served the St. Louis area since 1964 and remains family-owned today. The goal is simple on every visit: explain what is happening, give you clear options, and stand behind the work if something needs a second look.

A few things homeowners may want to know before scheduling:

• Family-owned since 1964. Martin-Jetco Heating and Air Conditioning has been part of the St. Louis-area HVAC community for decades, with long-term experience serving homes and businesses across the region. 
• Licensed, NATE-certified technicians. Every technician carries NATE certification, an independent HVAC credential that reflects tested technical knowledge. 
• Experience with multiple major brands. Martin-Jetco Heating and Air Conditioning works with trusted manufacturers, including York, Goodman, Daikin, Carrier, and Trane, so recommendations can be based on the home, comfort needs, and budget. 
• Clear recommendations before work begins. Our technician explains what they find, what the repair or replacement would involve, and what the cost looks like before you authorize the work. 
• Recognition from customers and industry organizations. Martin-Jetco Heating and Air Conditioning holds an A+ rating with the Better Business Bureau, has earned six Angie’s List Super Service Awards, and has been recognized multiple times as a York Dealer of the Year. 
• Follow-up when something needs attention. If a job needs a second look, the team comes back, takes responsibility, and works to make it right. 

Want to hear from homeowners who have worked with Martin-Jetco Heating and Air Conditioning? We invite you to read our 1,000+ five-star Google reviews before you schedule.

Get HVAC help from a team that understands St. Peters homes. Call Martin-Jetco Heating and Air Conditioning at (636) 205-1631 or contact us online.

Frequently Asked Questions

What zip code does Martin-Jetco Heating and Air Conditioning serve in St. Peters?

Martin-Jetco Heating and Air Conditioning serves all of St. Peters and the 63376 zip code, along with neighboring St. Charles County communities.

My St. Peters home was built in the 1980s or 1990s. What should I expect going into a replacement?

Homes from that period commonly have ductwork that was installed for older equipment and has never been assessed since. Our evaluation looks at the ductwork alongside the equipment so the estimate reflects the full project rather than just the unit. In some cases, duct sealing or resizing is as important as the equipment choice for actual comfort and efficiency.

The upper level of my two-story home is always warmer in summer. Is that a system problem?

Not always. In St. Peters' 1990s colonial and two-story construction, upper-level heat accumulation is often a duct distribution issue rather than a failing system. Our technicians measure airflow at each register and check the duct layout before recommending whether the fix is a correction to the existing system, a zoning adjustment, or equipment that was never properly sized for the floor plan.

How much does HVAC replacement cost in St. Peters?

• AC replacement with evaporator coil: approximately $5,500 to $9,200. 
• Complete system replacement: approximately $8,450 to $22,990 or more. Home size, ductwork condition, equipment type, and installation access all affect the final number. 

Call (636) 205-1631 or request an estimate online.

How much does AC repair typically cost in St. Peters?

• Minor repairs (capacitors, thermostats): $150 to $600
• Mid-range repairs (blower motors, evaporator coils): $500 to $2,000
• Major failures (compressors, control boards, heat exchangers): $700 to well over $1,000

Our technician confirms the exact cost after diagnosis and compares it against AC replacement before recommending anything. Call (636) 205-1631 to book a same-day assessment.

How much does furnace repair typically cost in St. Peters?

• Ignitor and flame sensor: $180 to $350
• Furnace capacitor: $150 to $350
• Blower motor: $500 to $1,400+
• Control board: $700 to $1,650
• Heat exchanger: $2,000 to $4,000

When a diagnosis comes back at the control board or heat exchanger level, our technicians compare the repair cost against furnace replacement before pointing in either direction. Call (636) 205-1631 for a diagnostic visit.

My house feels cool but humid even when the AC runs all day. What is causing that?

This is often a sizing problem. An oversized system cools the house quickly but shuts off before completing a full dehumidification cycle. The result is a thermostat that reads the right temperature but air that feels damp and uncomfortable. It can also happen when a system is aging and losing efficiency. Our technicians check system sizing, runtime patterns, and refrigerant charge before recommending whether the fix is equipment-related or a broader airflow issue.

My furnace starts, runs for a few minutes, then shuts off without heating the house. What does that mean?

That pattern almost always points to a safety shutdown mid-cycle. The most common trigger is a dirty filter restricting airflow enough to overheat the heat exchanger, which trips the limit switch and cuts the burners while the fan keeps going. Swapping the filter and letting the system cool often resolves it. If the short-cycling continues, the limit switch may be failing, a control board fault may be cutting the cycle short, or the heat exchanger may have developed a crack. Call (636) 205-1631 if a filter change does not hold, since a cracked heat exchanger is a safety issue.

Do heat pumps work well in St. Peters?

Today’s heat pumps are much better suited to Missouri winters than older models. If your home has ductwork in good condition, a heat pump may be worth comparing against a traditional furnace and AC system. During the evaluation, our technicians look at ductwork, heating demand, and energy goals before recommending the best fit.

How often should HVAC systems in St. Peters be serviced?

A spring inspection before cooling season and a fall inspection before heating season is the right interval for most homes. In St. Peters, where a large share of the housing stock is now in its second equipment cycle and ductwork from the original installation may never have been evaluated, consistent pre-season maintenance gives our technicians the best chance of catching problems early. 

Is financing available for HVAC work in St. Peters?

Yes. Financing is available for qualifying projects. Our evaluation also covers applicable Spire rebates, federal energy-efficiency tax credits, and any current seasonal promotions so the complete cost picture is clear before you decide.

Schedule HVAC Service in St. Peters

Whether you are dealing with a comfort problem that has never been properly diagnosed, weighing repair against replacement, or facing something that needs attention today, Martin-Jetco Heating and Air Conditioning can help. Call (636) 205-1631 or schedule your evaluation online.