HVAC questions answered for Shelbyville & Middle Tennessee.

Repair it if the system is under about 12 to 15 years old, the repair is a modest share of replacement cost, and it has been reliable. Consider replacing it when it is older, needs a major part such as a compressor, or has needed repeated repairs.

Age, refrigerant type, efficiency and how comfortable the house actually is all belong in the decision. An honest contractor will show you the failed part and give you both options with prices, then let you decide.

Most central air conditioners and heat pumps last roughly 12 to 15 years here, and gas furnaces often last 15 to 20 or more. Heat pumps work year-round in this climate, so they tend to sit at the shorter end of that range.

Regular maintenance, clean coils, the right refrigerant charge and good airflow all stretch those numbers. Neglect shortens them.

Often yes, but recharging it gets expensive. R-22 has not been produced or imported in the U.S. since January 1, 2020, so only recovered and reclaimed supply remains.

A small, fixable leak on an otherwise healthy system can still be worth repairing. A large leak or a failed compressor on an R-22 system is usually the point where replacement makes more sense. Ask for both numbers before you decide.

A free quote means you get a straightforward price for the work before anything begins, with no high-pressure sales.

Call or text (931) 224-8403 to set it up. If you’re weighing repair against replacement, ask for both options so you can compare.

No. An oversized system cools the air quickly, shuts off, and doesn’t run long enough to pull humidity out, which leaves the house cold and clammy.

The right size depends on the house: square footage, insulation, windows, sun exposure and ductwork. A hot house is often a duct, airflow or insulation problem rather than a size problem.

Common causes are a dirty filter or coil, low refrigerant from a leak, leaky or crushed ductwork, or a system that is undersized or failing. On the hottest July afternoons a healthy system may also run long cycles.

If it runs constantly and the house keeps getting warmer, turn it off and call. Running a struggling system can freeze the coil or damage the compressor.

Yes. Heat pumps are common across Middle Tennessee because winters are mostly mild with periodic hard freezes. On the coldest nights they lean on auxiliary heat strips to keep up.

Newer variable-speed and cold-climate heat pumps hold more of their capacity in the teens. In older or leakier homes, a gas furnace paired with a heat pump (a dual-fuel system) is another option.

Light frost in cold, damp weather is normal, and a heat pump melts it off with a defrost cycle that can send up a cloud of steam for a few minutes.

Heavy ice that covers the whole coil and doesn’t clear, or ice on top of the unit, is not normal. That points to a defrost problem, low refrigerant, a fan issue or water dripping from a gutter. Call for service.

AUX means the backup heat strips are helping the heat pump, which is normal in very cold weather and during defrost. EM HEAT (emergency heat) runs only the strips and shuts off the heat pump.

Use emergency heat only if the heat pump has failed, because strip heat costs much more to run. If AUX is on constantly in mild weather, something needs attention.

A furnace that lights and quits often has a dirty flame sensor, a clogged filter causing overheating, a venting problem, or a failing control or pressure switch.

These are safety controls doing their job, so don’t bypass them. Change the filter if it’s dirty, and if it keeps happening, call for a diagnosis.

Check that the thermostat is set to heat, the filter isn’t clogged and the breaker hasn’t tripped, then call. Never use an oven, grill or camp stove indoors for heat.

Close curtains, keep interior doors open to share warmth, and drip faucets on exterior walls to protect pipes. Use only space heaters designed for indoor use, plugged directly into the wall, with clearance from anything that can burn.

Not necessarily. In Middle Tennessee a modern heat pump is often the most efficient way to heat, and it cools too. Gas furnaces give hotter air on the coldest nights and make sense where gas is available and comfort in a deep freeze matters most.

A dual-fuel setup gives you both. The right answer depends on whether gas reaches your street, your ductwork, and what your current equipment has left in it.

The usual causes are a tripped breaker or blown fuse at the outdoor unit, a failed capacitor or contactor, low refrigerant, a frozen coil, or a thermostat set to “fan on” or heat.

Check the thermostat and filter. If the outdoor unit hums but the fan doesn’t spin, turn the system off at the thermostat and call. Running it that way can damage the compressor.

Ice usually means not enough air across the coil, from a dirty filter, closed vents or a failing blower, or not enough refrigerant from a leak.

Turn cooling off and run the fan only to thaw it, replace the filter if it’s dirty, and call for service. Don’t chip the ice off.

Middle Tennessee summers are humid, and an AC removes moisture only when it runs long enough. Oversized systems, a fan left on “ON” instead of “AUTO,” leaky ductwork and damp crawl spaces all leave a house clammy.

Setting the fan to AUTO is the first easy step. Beyond that, the fix may be airflow adjustments, duct repairs, crawl space moisture control or a dehumidifier.

Turn the system off at the thermostat and wipe up the water. The most common cause is a clogged condensate drain line or a full drain pan, and many systems have a float switch that shuts things off to prevent a flood.

Air handlers in attics can damage ceilings quickly, so call promptly. A frozen coil melting can also cause a sudden leak.

Around 75 to 78°F is a good balance of comfort and cost for most homes. Each degree warmer saves energy.

Avoid big swings, especially with a heat pump. Moderate setbacks while you’re away are fine; dropping it to 65 on a 95° afternoon won’t cool the house faster.

Usually it’s airflow: a crushed or disconnected duct, an undersized run, a closed damper, a missing return, or a room with lots of sun and little insulation.

These are often fixable without new equipment. Duct repairs and airflow balancing are a common answer.

Check it monthly and change standard 1-inch filters every 1 to 3 months. Change them more often with pets, during pollen season, or after construction or remodeling dust.

A clogged filter is one of the most common causes of frozen coils, overheating furnaces and high bills. Thicker media filters last longer; follow the label.

Twice a year is ideal for a heat pump, which works in both seasons: a cooling check in spring and a heating check in fall. A furnace with a separate AC also benefits from a spring and fall visit.

Maintenance includes coil cleaning, electrical checks, refrigerant pressures, drains, safeties and airflow. Redeemer offers preventive maintenance plans and seasonal tune-ups.

Gently rinsing loose grass and dust off the outside of the coil with a garden hose, with the power off at the disconnect, is fine. Don’t use a pressure washer, which bends the fins.

Keep 2 feet of clearance around the unit. A coil that is matted with lint or dirt needs a proper cleaning.

They can capture finer dust and pollen, but a filter that’s too restrictive for your system reduces airflow and can cause problems. Many homes do well with MERV 8 to 11.

If you want stronger filtration, a thicker media filter cabinet lets you filter better without choking the system.

Often it’s moisture: a dirty indoor coil, a standing drain pan, damp ductwork, or air pulled from a damp crawl space.

Cleaning the coil and drain, sealing duct leaks and fixing crawl space moisture usually take care of it. A persistent musty smell is worth having checked.

Start with the basics: the right filter changed on schedule, sealed return ducts so attic or crawl space air isn’t pulled in, and a clean coil.

From there, upgraded filtration and humidity control can help. Recommendations should fit your home, not a sales script.

Signs include rooms that never get comfortable, high bills, dusty rooms, and ducts in the crawl space or attic that are disconnected, crushed or sagging.

In many Middle Tennessee homes the ducts run through a crawl space or attic, so a leak there blows paid-for air outside the living space. Inspecting and repairing those runs is often one of the best-value fixes.

SEER2 measures cooling efficiency and HSPF2 measures heat pump heating efficiency. Higher numbers use less electricity. The “2” ratings came in with updated test procedures in 2023.

In the Southeast region, which includes Tennessee, most new split central air conditioners must be at least 14.3 SEER2 (13.4 SEER2 for larger units), and split heat pumps must meet at least 14.3 SEER2 and 7.5 HSPF2.

New residential air conditioners and heat pumps are moving away from R-410A to lower-global-warming refrigerants such as R-454B and R-32, under EPA rules that took effect starting in 2025.

Existing R-410A systems can still be serviced and repaired. If you replace a system, the new outdoor unit and indoor coil are installed as a matched set designed for the new refrigerant. Refrigerant handling requires EPA Section 608 certification, so it isn’t a DIY job.

It can be, if it’s compatible with your equipment and set up correctly. With a heat pump, the auxiliary heat settings matter most; a poorly configured thermostat can run expensive strip heat more than necessary.

Programmable schedules and moderate setbacks save money. A thermostat can’t fix bad ductwork or a failing system.

Possibly. TVA’s EnergyRight program works through local power companies such as Shelbyville Power System and Duck River Electric, and has offered incentives and financing for qualifying home upgrades. Offers change, so check EnergyRight or ask your power company before you buy.

We won’t promise a rebate we can’t confirm. Ask when you request a quote and we’ll point you to the current program.

Generally no. Closing many vents raises pressure in the ducts, can increase leakage and reduce airflow over the coil, and doesn’t save as much as people expect.

If a room is too hot or cold, the better fix is balancing the airflow.

Leave the house right away. Don’t flip light switches, use the phone inside or start a car in an attached garage. Once you’re outside and away from the house, call your gas utility or 911.

Don’t go back inside until the utility or fire department says it’s safe. Then have the furnace and gas appliances checked before relighting anything.

Get everyone out of the house into fresh air and call 911. Don’t try to find the source yourself.

Carbon monoxide can come from a furnace with a cracked heat exchanger or a blocked vent, a gas water heater, a generator or a car. Every home with gas appliances or an attached garage should have working CO alarms.

Usually yes. Replacing heating and cooling equipment generally requires a mechanical permit and inspection from the local codes office. Rules vary by city and county, so the contractor should confirm and pull the permit.

A permit and inspection protect you: they check gas piping, venting, electrical connections and clearances.

Ask for the contractor’s license information and check it on the Tennessee Department of Commerce & Insurance license verification search. The Board for Licensing Contractors licenses contractors, including mechanical and HVAC classifications, for projects of $25,000 or more.

For any job, ask about insurance and EPA Section 608 refrigerant certification, get the price in writing before work starts, and be wary of anyone who pressures you to decide on the spot.

Changing filters, keeping the outdoor unit clear and checking thermostat settings are safe homeowner tasks. Refrigerant, gas lines, burners and the high-voltage electrical parts inside the equipment are not.

Capacitors can hold a dangerous charge even with the power off, and refrigerant work legally requires EPA certification. Leave those to a professional.

Redeemer works by its own stated principles: honest, quality work, no high-pressure sales, fair and transparent pricing, and doing things right the first time.

In the company’s words: “As a Christian business owner, I treat every customer like family.” Calls, texts and messages to (931) 224-8403 are answered personally.