HVAC Company Serving Arnold, MO

Martin-Jetco Heating and Air Conditioning provides:

• AC Repair 
• Furnace Repair 
• Heat Pumps 
• Mini Splits 
• Geothermal
• Emergency HVAC 
• Indoor Air Quality 
• Commercial HVAC 
• Same-Day Service 
• Financing Available 

Serving Arnold and Jefferson County since 1964.

If your home is no longer heating or cooling the way it should, call (636) 205-1631 or contact us online to schedule a visit with a NATE-certified technician.

Arnold HVAC Quick Answers

• Do you offer emergency HVAC? Yes, 24/7
• Same-day service? Often available for morning calls
• Do you finance? Yes
• Do you repair all brands? Yes
• Do you install geothermal? Yes
• Do you work in 63010? Yes
• How much is AC replacement? $5,500 to $9,200
• How much is a complete system replacement? $8,450 to $22,990 or more

What Martin-Jetco Heating and Air Conditioning Handles in Arnold

Martin-Jetco Heating and Air Conditioning helps Arnold homeowners and businesses with heating, cooling, indoor air quality, maintenance, and specialty HVAC work.

Services include:

• Cooling. AC Repair, AC Installation, AC Replacement 
• Heating. Furnace Repair, Furnace Installation, Furnace Replacement 
• Flexible comfort options. Heat Pump Services, Ductless Mini-Splits 
• Specialty systems. Boilers and Geothermal Systems 
• Indoor air quality. Whole-home filtration, air scrubbers, humidifiers, dehumidifiers 
• Ongoing and urgent service. HVAC Maintenance, Emergency HVAC Service, Commercial Heating and Cooling

Martin-Jetco Heating and Air Conditioning repairs all major HVAC systems and works with leading equipment brands, including York, Goodman, Daikin, Carrier, and Trane, so you have options whether the next step is repair, replacement, or a larger system upgrade.

Should I Repair or Replace My HVAC System?

Repair makes sense when the system is under 10 years old, the repair is minor, and the equipment has been reliable. Replacement becomes the stronger case when:

• The system is 15 or more years old
• Repair costs are climbing toward the price of a new system
• The system still uses R-22 refrigerant, which is no longer produced
• Comfort problems persist despite repairs
• Energy bills keep rising with no clear cause

Our technicians give you both the repair cost and the replacement cost before recommending either direction.

How Much Does HVAC Replacement Cost in Arnold, MO?

Two categories cover most residential replacements in Arnold:

• AC Replacement with evaporator coil: approximately $5,500 to $9,200
• Complete HVAC system (furnace and AC): approximately $8,450 to $22,990 or more

What moves a project within those ranges:

• Home square footage and the tonnage the system needs to handle
• Ductwork condition, including whether resizing or sealing is needed
• Equipment efficiency level and whether variable-speed is appropriate
• Zoning systems for multi-level homes or finished lower levels
• Electrical updates required before installation can begin
• Indoor air quality additions included in the project
• Accessibility of the mechanical space

For Arnold homeowners, an AC replacement with evaporator coil typically runs approximately $5,500 to $9,200, while a complete HVAC system replacement ranges from $8,450 to $22,990 or more. The split-level and ranch homes common throughout Arnold's subdivisions have specific ductwork and sizing considerations that make an in-home evaluation the only reliable way to get a number tied to the actual property. Request an estimate online or call (636) 205-1631.

What Do Common HVAC Repairs Cost in Arnold?

When your HVAC system starts acting up, the first question is usually whether the repair will be small enough to make sense or large enough that replacement should at least be part of the conversation. These ranges can help you budget before a technician confirms the exact problem:

• 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, the technician gives you a firm cost and explains how it compares to what replacement would run, so you have the full picture before deciding anything. Want to know what the repair will actually cost? Call (636) 205-1631 today.

Is Your Original HVAC System Reaching the End?

Many Arnold homes built between 1975 and 1995 are now experiencing exactly what you would expect from equipment that age:

• Frequent repairs that are adding up
• Higher utility bills with no clear explanation
• Uneven temperatures from room to room or floor to floor
• Aging ductwork that was never sealed or balanced
• Failing compressors approaching the end of their service life
• Outdated refrigerants like R-22 that are costly to service

One of the most common calls we receive in Arnold is from homeowners with split-level homes where one level never seems to reach the thermostat setting. Before recommending equipment replacement, our technicians measure airflow throughout the home because many of these comfort issues are caused by duct design rather than a failing furnace or air conditioner.

If your system is showing any of these signs, the first step is a proper diagnosis, not an automatic replacement. Call (636) 205-1631 or schedule a visit.

What Happens When You Call for Emergency HVAC Service

Some HVAC problems can wait for a standard appointment. Others need faster attention because the home is already unsafe, uncomfortable, or at risk of further damage.

Call for emergency HVAC service if:

• Your furnace stops working during freezing weather 
• Your AC quits during extreme heat 
• The system is running but blowing no air 
• You notice burning smells, hot electrical components, or unusual sounds 
• A breakdown affects an older adult, young child, or someone with health concerns in the home 
• The issue could cause water damage, electrical trouble, or a larger system failure 

Martin-Jetco Heating and Air Conditioning offers emergency HVAC service in Arnold around the clock, every day of the year. Morning calls often lead to same-day visits, sometimes that afternoon. Evening, weekend, and holiday calls are dispatched as soon as a technician is available.

If the issue feels urgent, call (636) 205-1631. Martin-Jetco Heating and Air Conditioning can help you determine the next step and dispatch emergency HVAC service when needed.

How to Bring the Replacement Cost Down

A new HVAC system is a significant purchase, and most homeowners do not plan for it until the old system is already failing. Martin-Jetco Heating and Air Conditioning understands that replacement is not always easy to pay for all at once, which is why we offer several ways to help make the cost more manageable.

During your estimate, we can review options such as:

• Financing. Financing for qualifying projects turns a lump sum into a fixed monthly payment.
• Utility rebates. Filed by Martin-Jetco Heating and Air Conditioning on your behalf at installation, so you do not have to track the paperwork.
• Federal energy-efficiency tax credits. Applicable to qualifying heat pumps and high-efficiency furnaces. The credit amount depends on the equipment and the tax year, and it can be significant on the right installation.
• Seasonal promotions. Periodically available and worth asking about at the time of your estimate.

During the in-home evaluation, Martin-Jetco Heating and Air Conditioning reviews which of these apply to your project and shows you the equipment cost, the financing option, and any credits or rebates side by side.

What Causes Uneven Temperatures in Arnold Homes?

After 60 years of working on homes across the St. Louis region, we have seen how often comfort problems come from more than one broken part. The layout of the house, the age of the system, the way the lower level was finished, and even the location of the outdoor unit can all affect how well your HVAC system performs.

If certain rooms never feel right, the basement stays humid, or your system seems to work harder than it should, one of these common home conditions may be part of the reason:

• Ranch and split-level layouts with airflow imbalances. These floor plans dominate Arnold's housing stock. Long horizontal duct runs in ranch homes often leave far bedrooms underserved, and split-levels frequently have one level that runs noticeably warmer or cooler than the others, even when the system itself is functioning correctly.
• Systems built during the city's growth years that are now aging out. Homes built in the late 1970s through the 1990s represent a large share of Arnold's housing stock. Equipment installed during that period is either already been replaced once or is now reaching the point where repair calls are becoming more frequent and more expensive.
• Basement humidity near the river. Homes in the lower-lying areas of Arnold near the Meramec and its floodplain have dealt with flooding events in 2015 and 2017 that affected hundreds of properties. Even homes that never flooded directly deal with higher ambient moisture in finished lower levels during summer months, which affects how hard the HVAC system works and how effective it is at maintaining comfortable humidity levels indoors.
• Finished walkout lower levels that were never part of the original duct plan. Many Arnold homeowners have finished out lower levels that the original duct system was not designed to condition. These spaces often run significantly warmer than the main floor in summer and cooler in winter, and the fix is usually a duct extension, a zoning adjustment, or a dedicated ductless mini-split.
• Outdoor equipment in tight or wooded settings. Arnold's rolling terrain and wooded lot lines mean condenser units sometimes sit in spots with limited clearance or heavy shade that reduces how efficiently the system can reject heat during summer.

Why Is My Upstairs Hotter Than Downstairs?

Heat rises, and in a split-level or two-story home, upper levels accumulate warmth in summer that the thermostat on the main floor never captures. But the most common cause in Arnold homes is not the equipment — it is the duct system.

Duct runs in split-level and ranch homes from the 1970s through 1990s were sized to meet code minimums, not to deliver balanced airflow to every level. Upper levels often receive inadequate supply air, and return air sizing on upper floors is frequently undersized as well. The result is a main floor that stays comfortable while bedrooms or upper rooms run consistently warmer.

Solutions include air balancing, zoning systems with separate thermostats per level, variable-speed equipment that runs longer cycles at lower capacity, or aductless mini-split for the affected level. Our technicians measure static pressure and airflow at every register before recommending anything.

Why Is My Basement Humid?

Arnold's proximity to the Meramec River floodplain is the starting point for this answer. The 2015 and 2017 flooding events affected hundreds of Arnold properties directly, and even homes that never flooded deal with higher ambient moisture in crawl spaces and lower levels during summer months because of the surrounding terrain.

When a finished basement feels damp despite the AC running upstairs, two things are usually happening:

• The AC system is oversized. An oversized unit cools the main floor quickly and shuts off before completing a full dehumidification cycle. The thermostat reads correctly; the humidity does not get addressed.
• The lower level was never part of the original HVAC plan. Walkout basements, game rooms, home offices, and finished bonus rooms added after original construction rely on whatever conditioned air drifts down from above. That is not enough to manage the moisture load in a river-adjacent community.

Solutions include a dedicated whole-home dehumidifier, a ductless mini-split for the lower level, duct modifications to properly supply the space, or a zoning system. Indoor air quality upgrades like air scrubbers and filtration also help address the broader moisture and mold risk that comes with Meramec-area properties.

Call (636) 205-1631 or schedule a diagnostic visit if basement humidity has been an ongoing issue.

Why Does My Split-Level Never Feel Comfortable?

This is one of the most consistent complaints our technicians hear from Arnold homeowners, and it almost always traces back to duct design rather than failing equipment.

Split-level homes have distinct levels separated by partial flights of stairs, which means heat accumulates differently on each floor. The ductwork serving those levels was typically sized to meet code at the time of construction, not to deliver comfort throughout the home. Long horizontal runs lose supply air before reaching far rooms. Upper levels lack adequate return air. The blower motor works against higher static pressure than it was designed for, reducing efficiency and accelerating wear.

Before recommending equipment replacement on a split-level comfort complaint, our technicians always measure airflow at each register and assess the duct layout. In many cases, air balancing, a zoning system, or a ductless mini-split for the problem level resolves the issue for significantly less than a full system replacement.

Why Does My Basement Feel Different From the Rest of My Arnold Home?

Many Arnold homes have walkout basements, finished lower levels, bonus rooms, home offices, and exercise rooms that were added or finished long after original construction. These spaces consistently underperform on comfort because they were never part of the original duct plan.

What Arnold homeowners typically need for finished lower levels:

• Duct modifications to properly extend supply and return air into the finished space
• Air balancing to redistribute existing airflow when the system has available capacity
• Zoning systems so the lower level has its own thermostat independent of the main floor
• Ductless mini-splits for independent heating and cooling without relying on the main system
• Dedicated dehumidifiers for moisture control in Meramec-adjacent properties

Our technicians evaluate the existing system capacity, ductwork, and lower-level layout before recommending which approach fits the home.

Commercial HVAC in Arnold

Martin-Jetco Heating and Air Conditioning handles commercial heating and cooling for the full range of Arnold business types:

• Restaurants and food service along Jeffco Boulevard and Arnold Commons
• Retail tenants at Arnold Commons and along Missouri State Road
• Medical offices and professional suites near Jefferson College and Highway 141
• Churches and community facilities throughout Jefferson County
• Warehouses and light industrial properties near Interstate 55
• Professional offices along the Jeffco Boulevard and Arnold Commons corridors

Commercial systems have different load profiles, uptime requirements, and service needs than residential HVAC. Our team assesses each commercial property on its own terms.

Neighborhoods & Areas We Serve in Arnold

Martin-Jetco Heating and Air Conditioning serves homeowners and businesses throughout Arnold, including the 63010 zip code and surrounding Jefferson County communities. Service is available across established and newer residential subdivisions such as Strawberry Ridge, Apple Valley, Hickory Ridge, Fox Pointe, and Fox Run.

The team serves homes and businesses near Arnold City Park and its 8-acre fishing lake, Strawberry Creek Nature Area, Ferd B. Lang Park, Flamm City Park, the Arnold Recreation Center, the Arnold Branch of Jefferson County Library, and the Jefferson College Arnold campus on Missouri State Road.

Families connected to Fox C-6 School District schools can call Martin-Jetco Heating and Air Conditioning for HVAC service throughout the Arnold area, including homes near Rockport Heights Elementary, Richard Simpson Elementary, Meramec Heights Elementary, Sherwood Elementary, Lone Dell Elementary, Ridgewood Middle School, Fox Middle School, and Fox Senior High School.

Commercial HVAC service is available near the Jeffco Boulevard corridor, Arnold Commons, Highway 141, Missouri State Road, and the Interstate 55 business and retail areas.

A Reputation Built Across 60+ Years of Service Across the St. Louis Region

When you are choosing an HVAC company, you want to know the people coming to your home. Martin-Jetco Heating and Air Conditioning has built that record through decades of local service, trained technicians, manufacturer recognition, and feedback from homeowners across the region.

• More than 1,000 5-star Google reviews. Homeowners across the region have shared what it was like to have Martin-Jetco Heating and Air Conditioning in their homes. 
• NATE-certified technicians on every job. The industry’s leading independent credential, earned by examination. 
• A+ rating with the Better Business Bureau. Reflects how issues, when they come up, are handled and resolved. 
• Six Angie’s List Super Service Awards. Earned through documented customer feedback over multiple years. 
• York Dealer of the Year, more than once. Manufacturer recognition based on training standards, service consistency, and verified customer satisfaction. 

If you’d like to hear from customers before you call, start with our reviews. They can help you get a feel for the service before you schedule.

Keep Your System Running Before Problems Develop

The Martin-Jetco Heating and Air Conditioning Home Comfort Agreement puts your HVAC maintenance on a schedule that runs ahead of peak demand rather than behind it.

What membership covers:

• A full inspection before cooling season and before heating season, so the system is evaluated while conditions are mild, not during a July heat wave
• Complete safety and performance check at each visit, with any developing issues surfaced and explained
• 20% off parts and labor on any repair work between scheduled visits
• No extra charge for after-hours or weekend service calls
• Priority scheduling when an unplanned issue comes up
• Reduced diagnostic fee on calls during regular business hours

Learn more about the Home Comfort Agreement or call (636) 205-1631 to add it to your next appointment.

Frequently Asked Questions

What zip code does Martin-Jetco Heating and Air Conditioning serve in Arnold?

Martin-Jetco Heating and Air Conditioning serves all of Arnold and the 63010 zip code, along with neighboring Jefferson County communities.

My home was built in the 1980s or 1990s. Is the HVAC system likely due for replacement?

It depends on what has been replaced and when. The original equipment in homes from that period would now be 30 to 40 years old, well past the typical service window. If the system has already been replaced once, it may have another 10 to 15 years depending on how it was maintained. The most reliable answer comes from a technician who can look at the equipment, check the service history, and tell you whether the system is performing within expected parameters or showing signs of decline.

My split-level home has one level that never feels right. Is that a system problem?

Not always. Split-level layouts with long duct runs to certain levels are one of the most common airflow complaints in Arnold's housing stock, and the cause is often duct-related rather than a failing system. A technician should measure airflow at each register, check the duct layout, and determine whether the fix is a duct correction, a zoning adjustment, or an equipment issue before recommending anything.

Should I replace both the AC and furnace together?

Often, yes. When both systems are aging, replacing them together means matched equipment, a single installation visit, and a fresh maintenance schedule. If one is newer and still performing well, replacing only the failing unit is usually the right call. Our technicians assess both systems and lay out the practical and financial case for each approach.

Is zoning worth it?

For Arnold homes with split-level layouts, finished lower levels, or rooms that never match the thermostat setting, zoning is often worth the investment. A zoning system gives each level or area its own thermostat and control, independent of the rest of the house. It is less expensive than it once was and frequently resolves comfort problems that equipment replacement alone cannot fix.

How much does it cost to replace an HVAC system in Arnold?

Two ranges cover most projects:

• AC with evaporator coil: approximately $5,500 to $9,200
• Complete system (furnace and AC): approximately $8,450 to $22,990 or more

Ductwork condition, home size, equipment type, and installation access all move the number within those ranges. Call (636) 205-1631 or request an estimate online for a figure based on your home.

How much does AC repair typically cost in Arnold?

Repair costs by component:

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

The technician gives you the exact figure after diagnosis and explains how it compares to AC replacement before any work starts. Call (636) 205-1631 to schedule a diagnostic visit.

How much does furnace repair typically cost in Arnold?

Common repair ranges to plan around:

• 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

At the control board and heat exchanger level, furnace replacement often makes more sense than repair, especially on an older system. Call (636) 205-1631 for a same-day diagnostic.

My finished basement always feels humid in summer even when the AC is running. What causes that?

Homes near the Meramec River bottomland deal with higher ambient moisture than homes on higher ground, and finished lower levels in those areas tend to hold summer humidity even when the main floor is comfortable. Two common causes: the AC system is oversized and short-cycling without running long enough to pull moisture from the air, or the lower level was never properly integrated into the home's HVAC plan. A technician should evaluate system sizing, airflow to the lower level, and whether a dedicated dehumidifier or a ductless mini-split for that zone would resolve the problem.

My AC runs constantly but the house does not cool down. What should I check first?

Start with the filter. A clogged filter restricts airflow enough to prevent effective cooling and can eventually freeze the evaporator coil. Beyond that, common causes include low refrigerant from a leak, a dirty outdoor condenser coil, a failing capacitor, or ductwork that is leaking conditioned air before it reaches the rooms that need it. In Arnold's ranch homes with long duct runs, that last one is more common than most homeowners expect. A technician needs to check refrigerant charge, measure airflow, inspect the condenser, and evaluate the duct system before confirming what the fix requires.

My furnace turns on but stops heating before the house reaches temperature. What is happening?

This usually points to a safety limit switch tripping mid-cycle, which shuts the burners down before the heating cycle completes. The most common trigger is restricted airflow from a clogged filter causing the heat exchanger to overheat. It can also happen from a failing flame sensor that loses signal during a cycle, or a heat exchanger that is cracked and triggering the safety system by design. Because a cracked heat exchanger is a safety issue, not just a comfort issue, call (636) 205-1631 if a filter change does not resolve the problem.

Should I buy a heat pump?

Heat pumps make sense for many Arnold homes. Current models handle Missouri winters considerably better than older heat pump designs, and they provide heating and cooling in one system. The key variables are ductwork condition and peak winter heating load. Our technicians evaluate both before recommending a heat pump, a dual-fuel setup, or a traditional furnace and AC combination.

How often does an HVAC system in Arnold need to be serviced?

Before cooling season in spring and before heating season in fall covers most homes. In Arnold specifically, where a large share of the housing stock now has systems approaching or past the 15-year mark, consistent maintenance tends to surface developing issues before they become failures. Documented HVAC maintenance also keeps most manufacturer warranties active, which matters when you have invested in a replacement system and want the coverage to hold.

Is financing available for HVAC projects in Arnold?

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

Get Clear HVAC Answers for Your Arnold Home

Whether a system is showing its age, a repair estimate has you questioning whether replacement makes more sense, or you want to get ahead of another summer, Martin-Jetco Heating and Air Conditioning can help you sort it out. Call (636) 205-1631 or schedule your evaluation online.