Heating &amp; Cooling: questions, answered with sources

What does an AC repair technician check first?

A technician usually starts with what you noticed, then rules out the simple causes that only look like a breakdown: the thermostat's mode and fan settings, a clogged air filter and power to the outdoor unit. After that come the electrical parts, motors, coils and drain, and last the refrigerant charge, which only an EPA Section 608 certified technician may test.

How much does AC repair cost in Virginia?

Virginia has no set price for AC repair. Each licensed HVAC business sets its own, and the total depends on the diagnostic fee, which part failed, the refrigerant your system uses, whether a leak has to be found and fixed, and the system's age. Get a written, itemized estimate before you approve the work.

Does an HVAC technician need a license in Virginia?

Yes. Virginia law requires anyone doing heating, ventilation and air conditioning work for the public for pay to hold a tradesman licence from the Board for Contractors, or to work under the supervision of a licensed HVAC tradesman. The business doing the work also needs its own contractor licence, and anyone who handles refrigerant needs federal EPA Section 608 certification.

Why is my air conditioner blowing warm air?

Usually something is stopping the cooling cycle or the airflow: the thermostat is set wrong or its fan is on "On", the air filter is clogged, the indoor coil has frozen, the outdoor unit is dirty or not running, a blocked condensate drain has shut the system down, or refrigerant is leaking. The thermostat and filter are yours to check; the rest needs a licensed technician.

How often should my air conditioner be serviced?

Once a year for most central air conditioners, ideally in spring before the cooling season, by a licensed HVAC technician. ENERGY STAR recommends annual pre-season check-ups, and Carrier, Trane and American Standard say the same. Between visits, check the air filter monthly and keep the outdoor unit clear. A heat pump, which also heats your home, gets a fall check as well.

Air Duct Cleaning

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What are the warning signs of a duct cleaning scam?

The classic duct cleaning scam starts with a rock-bottom coupon price and ends with a much bigger bill for mold removal or repairs you did not ask for. Other red flags: sweeping health claims, a push to clean ducts as routine maintenance, claims of EPA certification, mold you are never shown, sprayed chemicals you do not understand, and no written price before work starts.

Why is there black dust around my air vents?

Black dust around vents is usually soot or dirt carried by the air. Common causes are candle or incense soot that settles on cool surfaces near vents, dirt slipping past a loose or clogged filter, dust pulled into leaky ducts from an attic or crawl space, and mold where registers sweat in humid weather. First rule out soot from any fuel-burning appliance: it is a carbon monoxide warning sign.

Boilers & Radiant

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How does a hot water boiler heating system work?

A hot water boiler heats water with gas, propane, oil or electricity, and a pump circulates it through pipes to radiators, baseboards or radiant floors, which give the heat off into your rooms. The cooler water returns to the boiler to be reheated. An expansion tank, a relief valve and the boiler's controls keep the sealed loop at a safe pressure and temperature.

How much does a new boiler cost in Virginia?

There is no published Virginia price list for a new boiler; your number comes from written quotes after a contractor has seen the house. The price moves with the boiler type, its size from a heat-loss calculation, the number of zones, venting and gas piping changes, how you heat household water, and the permit. The federal tax credit for gas and oil boilers ended with 2025.

Who can service a gas boiler in Virginia?

A licensed HVAC or plumbing tradesman, working for a licensed contractor. Virginia's rules list boilers under both HVAC work and plumbing work, a gas-fitter-only licence does not cover boilers, and new or altered gas piping is gas fitting work. Check the technician's and the company's licences on DPOR's License Lookup before anyone opens the boiler.

Why is my boiler losing pressure?

A hot water boiler that keeps losing pressure is usually losing water. The common causes are a leak in the piping, a radiator valve or the boiler itself, a relief valve that opens because a failed or undersized expansion tank lets pressure spike when the water heats, or a leaking air vent. Note the gauge readings and any water you see, and have a licensed technician find the cause.

How often should a boiler be serviced?

Once a year, ideally in early fall before the heating season. Navien says all residential boilers should be inspected and serviced annually by a professional, and the EPA and U.S. Fire Administration both call for a yearly professional inspection of heating equipment. Between visits, keep the area clear, watch the pressure gauge and vent pipe, and call sooner if anything changes.

Duct Cleaning

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How do I clean air vents and return grilles?

Turn the system off, vacuum the face of each supply register and return grille with a brush attachment, then take the covers off, wash them in warm soapy water, dry them fully and refit them. Wipe only the lip of the duct you can reach and keep water out of the ductwork. A dusty return grille is normal; dust blowing out of supply vents is a job for a pro.

How much does air duct cleaning cost in Virginia?

EPA's consumer guide, first published in 1997, put typical duct cleaning at $450 to $1,000 per heating and cooling system, depending on the services offered, system size, access, climate and contamination. Some companies bill by the hour instead. Today's price for your Virginia home is whatever a written, itemised quote says, so get three and treat a coupon price far below the rest as a sales pitch.

Is air duct cleaning worth it?

Usually not as routine maintenance. EPA says duct cleaning has never been shown to prevent health problems and recommends it as needed, not routinely. It suggests considering a cleaning for substantial visible mold in hard-surface ducts, rodents or insects in the ducts, or ducts clogged with dust and debris or releasing particles from the supply registers. Then it is worth paying a careful company, once the cause is fixed.

Why is my house so dusty even with clean air ducts?

Because ducts are only one of many sources of household dust. EPA notes that much of the dirt in ducts sticks to duct surfaces, and that pollutants from outdoors and from cooking, cleaning or just moving around can cause greater exposure than dirty ducts. The usual culprits are a dirty or bypassed filter, a system that rarely runs, leaky return ducts in an attic or crawl space, and dry dusting.

How often should air ducts be cleaned?

There is no set schedule. EPA does not recommend routine duct cleaning, only cleaning as needed, and suggests considering it for substantial visible mold growth in hard-surface ducts, vermin in the ducts, or ducts clogged with dust and debris or releasing particles from the supply registers. What keeps ducts clean between those events is regular filter changes, dry ducts and a yearly check of the system.

Ductwork

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How do I seal leaky air ducts?

Seal the duct joints you can reach in the attic, crawlspace, basement or garage with duct mastic or metal-backed foil tape, never cloth duct tape, then seal the registers where they meet the floor, wall or ceiling and insulate ducts in unconditioned space. In an older home, treat old duct wrap and tape as possible asbestos and leave them alone, and hire an HVAC contractor for hidden or return-side ducts.

How much does new ductwork cost in Virginia?

There is no dependable statewide price, because the cost turns on how much duct is replaced, where it runs, what it is made of and what the locality requires. Sealing and repairing existing ducts usually cost less than replacement. Get written quotes that separate the duct work, insulation, testing and permit, and check whether you qualify for no-cost weatherization help.

Do you need a permit to replace ductwork in Virginia?

It depends on the scope and your locality. Virginia's building code requires a permit for installations or alterations involving mechanical systems. Fairfax County requires a mechanical permit for new or replacement duct installation; Pittsylvania County requires one to add, move or remove ductwork but not to replace it with the same type, size and location. Ask your building department before work starts, including for sealing or repair.

Why are some rooms in my house hotter than others?

Usually because those rooms get less conditioned air or gain more heat than the rest of the house. The common causes are leaky, crushed or disconnected ducts, a closed door with no return path, blocked registers or a dirty filter, sun and weak attic insulation, an upper floor under a hot attic, and a system or duct layout that was never sized room by room.

How long does ductwork last?

How long ductwork lasts depends on its condition more than a number of years: how well the joints, seals, insulation and flexible duct hold up, and whether the ducts stay dry and undamaged. Inspect the ducts you can reach once a year, and have an HVAC contractor repair or replace sections that are collapsed, disconnected or have wet or moldy insulation.

Furnace Replacement

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What does replacing a furnace involve?

Replacing a furnace is usually a one-day job for a licensed HVAC contractor: a heating-load check to size the new unit, a permit, removing the old furnace, connecting the new one to the ductwork, fuel or power supply, venting and condensate drain, then start-up testing and an inspection. In Virginia, swapping a gas or oil furnace needs a permit.

How much does a new furnace cost in Virginia?

There is no published Virginia price. When we checked on October 26, 2026, Trane's 2026 national guide put its installed gas furnaces at $5,093 to $6,386 for models rated up to 80% AFUE and $6,630 to $8,390 for models rated up to 96% AFUE, before tax. Your quote depends on efficiency, size, staging, venting and duct changes, and the permit, so compare itemized written quotes.

When is it time to replace a furnace?

Start planning a replacement once the furnace is past about 15 years and showing its age: repairs every winter, rising fuel bills, uneven heat, new noises or a yellow burner flame. A safety finding such as a cracked heat exchanger needs a licensed diagnosis at any age. Have a licensed HVAC business inspect it and price both repair and replacement before it fails in the cold.

Why is my new furnace short cycling?

Common causes of a new furnace shutting off after a few minutes include a furnace oversized for the house, airflow starved by a clogged filter, closed vents or undersized ducts, and a badly placed or misconfigured thermostat. A venting problem or a dirty or faulty flame sensor can also make its safety controls shut it down. Check the filter and vents, then call the installer back.

How long does a furnace last?

A well-maintained gas furnace typically lasts 15 to 20 years, and electric furnaces often last 20 to 30. Some reach 30 years, but that is uncommon. Correct sizing, a good installation, regular filter changes and a yearly professional tune-up do the most to get a furnace to the long end of that range.

Geothermal

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How does a geothermal heat pump work?

A geothermal heat pump trades heat with the ground instead of the outdoor air. Fluid in a buried pipe loop picks up the earth's steady warmth in winter, and an indoor heat pump concentrates that heat with a compressor and blows it through your ducts. In summer the cycle reverses and the loop carries heat from the house back into the cooler ground.

How much does a geothermal system cost in Virginia?

No reliable Virginia price is published, because the ground loop, the lot and the house set most of the cost. Expect geothermal to cost more up front than an air-source heat pump, plus a state well-permit fee for a closed-loop geothermal well system and local permits. The 30% federal tax credit is not available for systems placed in service after December 31, 2025.

Is geothermal heating worth it in Virginia?

It can be, for a house you plan to keep, with room for a loop and an old heating and cooling system due for replacement. Geothermal costs more up front than an air-source heat pump but uses far less electricity than resistance heat and lasts longer. With the 30% federal credit ended after 2025, have a geothermal designer compare it against an air-source quote.

Why is my geothermal system not keeping my house warm?

The usual causes are a thermostat or backup-heat setting, a dirty filter or closed registers, a unit in lockout, backup heat that has lost power, or a loop or well-water problem. Geothermal systems also run long cycles with milder air, which can feel like a fault. Check the thermostat, filter and fault lights, then call a licensed HVAC technician.

How long does a geothermal system last?

A geothermal system has two lifespans. The buried loop of high-density polyethylene pipe lasts for decades, and WaterFurnace, citing the Department of Energy, gives it a rated material life of more than 100 years. The indoor heat pump wears out sooner, about 25 years on average by the same estimate, and regular service, clean filters and a protected loop help it get there.

Heat Pump Service

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What does heat pump maintenance include?

A heat pump maintenance visit is a licensed technician's check of the outdoor unit and the indoor air handler: refrigerant charge and leaks, electrical connections, coils, airflow, the condensate drain, the reversing valve, the defrost cycle and the backup heat. The fall visit should test defrost and aux heat. Your share between visits is the filter and a clear space around the outdoor unit.

How much does annual heat pump service cost in Virginia?

Virginia has no set price. Licensed HVAC businesses price heat pump service themselves, and the total depends on one visit or two, how many systems you have, whether coil cleaning and refrigerant are included, and any repairs found. As a national reference, a Trane guide updated in February 2026 put a two-visit maintenance plan at $175-$350 a year. Qualifying Dominion Energy customers may get a tune-up at no cost.

Is a heat pump maintenance plan worth it?

Often, yes, for a heat pump: it heats and cools, so it needs a spring and a fall visit, and a plan makes sure both happen. It is worth it when each visit follows a full checklist, the price is no more than two single visits, and the renewal terms are clear. It is not when visits are a quick look or the plan is really a repair warranty.

Why is my heat pump running constantly in winter?

In real cold, long run times are normal: a heat pump's output falls as the outdoor air gets colder, so it may run almost nonstop to hold the temperature. Running constantly in mild weather is not normal. Check that the thermostat is on Heat, the filter is clean and the outdoor unit is clear; if it still runs nonstop, a licensed technician should look for refrigerant, defrost or fan faults.

How often should a heat pump be serviced?

Have a licensed technician service a heat pump at least once a year, and ideally twice: in spring before cooling season and in fall before heating season, because it does both jobs. The fall visit is the one that tests defrost and backup heat. Between visits, check the filter monthly and keep the outdoor unit clear of leaves, shrubs and heavy snow.

Heat Pumps

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How does a heat pump work in cold weather?

Even freezing air holds some heat. A heat pump's outdoor coil runs colder than the air around it, so its refrigerant soaks up that heat, the compressor concentrates it and the indoor coil releases it into your ducts. As temperatures fall it delivers less heat per unit of electricity, defrosts its outdoor coil from time to time, and leans on backup heat on the coldest days.

How much does a heat pump cost in Virginia?

It depends on the house, but a manufacturer's own guide gives a starting point. When we checked on October 26, 2026, Trane's 2026 national cost guide put its installed standard heat pumps at $8,313 to $15,608 and its cold-climate heat pumps at $7,983 to $17,012. Sizing, ductwork, backup heat, electrical work and the permit move a Virginia quote up or down.

What should I ask a contractor before installing a heat pump?

Ask for their DPOR licence number and class, then how they will size the system (a Manual J load calculation, not a rule of thumb), which model and cold-climate rating they propose, how backup heat will be sized and set, whether they will test the ducts, airflow and refrigerant charge, who pulls the permit, and what the written contract and warranty cover.

Why does my heat pump blow cool air in winter?

Often it is working normally: heat pump air runs around 85–100°F, cooler than a furnace's, and the system blows cooler air for a few minutes while it defrosts the outdoor coil. Check that the thermostat is on Heat with the fan on Auto. Cold air that lasts, heavy ice, or aux heat that never shuts off points to a fault a licensed technician should find.

How do I keep a heat pump running well in winter?

Have a licensed technician service it in the fall, keep the filter clean, and keep the outdoor unit clear of snow, leaves and dripping gutters with about two feet of space around it. Hold a steady thermostat setting on Heat, raise it gradually, keep emergency heat for real failures, and call for service when ice will not clear or aux heat runs in mild weather.

Heating Repair

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What happens during a furnace repair visit?

The technician asks what the furnace is doing, checks the thermostat, filter and power, then watches the furnace try to start and reads any error code on its control board. Once the failed part is found, you get the diagnosis and a price before the repair. On a gas furnace, ask whether the visit includes the combustion checks a yearly check-up covers.

How much does furnace repair cost in Virginia?

There is no official Virginia price for furnace repair. Licensed HVAC businesses set their own rates, and the bill depends on the service call fee, which part failed, labour, when the visit happens and the furnace's age and fuel. Get the diagnosis and an itemized price in writing before work starts. Qualifying households can get state help with heating equipment repair.

Should I repair or replace my furnace?

Repair it if the furnace is under about 15 years old, safe to run and the fix is a fraction of a new furnace's price. Consider replacing it once it is past 15 years, needs repairs often, a repair would cost more than half the price of a new one, or there is a safety problem such as a cracked heat exchanger.

Why is my furnace blowing cold air?

Most often the thermostat fan is set to On instead of Auto, so the blower runs between heating cycles. Other causes are a clogged filter that trips the furnace's high-limit switch, a dirty flame sensor, an ignition or pilot problem, a blocked condensate drain or a failing control board. A short burst of cool air at startup is normal.

How do I keep my heating system from failing in winter?

Have a licensed technician check the furnace or heat pump every fall, before the busy season. Between visits, keep the filter clean, keep supply vents and returns open, keep the outdoor vent pipes and heat pump unit clear of snow and ice, put carbon monoxide alarms on every level, and call early when the system starts making new noises or short cycling.

Humidifiers & Dehumidifiers

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How do I choose a dehumidifier for my basement?

Start with how damp the basement is and how big it is. ENERGY STAR's chart suggests 20 to 30 pints a day for a slightly to moderately damp space under 2,000 square feet, and more for wetter or larger ones. Pick a certified model with a built-in humidistat, a drain you can live with, and a low-temperature rating if the basement stays below 65°F.

How much does a whole-house humidifier cost in Virginia?

The price depends on your house: the humidifier type, how close a water line and drain are to the furnace, any bypass ductwork, wiring the control, a permit if your building department requires one, and how often your model needs a new water panel. Get a written quote from a licensed HVAC contractor that lists each of those as its own line, and compare quotes line by line.

Is a whole-house dehumidifier worth it?

It is worth it when the whole house, not just the basement, keeps reading above about 55 percent humidity while the air conditioning works properly. ENERGY STAR says these units carry significant benefits for relatively well sealed homes with central air. If only one area is damp, a portable unit is the simpler, cheaper first step. Installation ties into ducts and a drain, so hire a licensed HVAC contractor.

Why is my house so humid in summer?

Moisture is getting in, or being made inside, faster than the air conditioner takes it out. Common causes are an oversized AC that cools quickly and shuts off, a thermostat fan left on, mild muggy days when the AC barely runs, gaps that let damp outdoor air in, and moisture from showers, laundry or a damp basement. Measure first, then check the fan setting, drains and vents.

What humidity should I keep my house at?

Keep indoor relative humidity between 30 and 50 percent, and do not let it sit above 60 percent, where mold grows. In summer that usually means running the air conditioner or a dehumidifier. In winter, aim for the lower part of the range on cold days, and turn a humidifier down if water condenses on the windows.

HVAC Maintenance

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How do I clear a clogged AC condensate drain line?

Turn the system off, find the drain line's access point near the indoor unit and its exit outside, then pull the clog out with a wet/dry vacuum at the outdoor end. Pour distilled vinegar or a PVC-safe cleaner into the access point, let it sit, and flush with water. Call an HVAC technician if water has damaged ceilings or the clog keeps coming back.

How much does an HVAC tune-up cost in Virginia?

There is no official Virginia price for a tune-up: licensed HVAC businesses set their own, and the total depends on how many systems you have, whether one or two seasonal visits are included, gas furnace checks, and extras such as refrigerant or drain cleaning. Get a written, itemized quote. Dominion Energy customers who meet its income limits, or its age and income limits, may get one at no cost.

Are HVAC maintenance plans worth it?

Often, if the plan delivers the spring cooling and fall heating check-ups ENERGY STAR recommends, at a price no higher than booking those visits one at a time, from a licensed Virginia business. It is not worth it if it covers less than a real tune-up, if you would not use the visits, or if it renews automatically on terms you have not read.

Why is my HVAC system running all the time?

Start with the easy causes: a thermostat set far below room temperature, the fan switched to On instead of Auto, a lamp or TV warming the thermostat, a dirty filter, closed vents or a blocked outdoor unit. Very hot or cold weather also means long run times, especially for heat pumps. Dirty coils, ice, a stuck contactor, low refrigerant or an undersized system need a technician.

How often should I change my furnace filter?

Check it every month while the heat or air conditioning is in heavy use, and change it when it looks dirty. Manufacturers typically recommend replacement every 60 to 90 days, and the interval your filter's maker gives is the one to follow. If the old filter comes out heavily soiled, consider changing it more often; homes with pets, smokers or allergies may need shorter intervals.

Indoor Air Quality

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How do I improve indoor air quality at home?

Work in the order the EPA recommends: cut the sources of pollution first, bring in more outdoor air second, and filter what is left. In practice that means fixing leaks and keeping humidity below 60 percent, running kitchen and bath fans that vent outside, using a MERV 13 furnace filter if your system can take one, testing for radon and fitting carbon monoxide alarms.

How much does a whole-house air purifier cost in Virginia?

There is no set Virginia price. In a Trane article dated March 20, 2026, checked on October 26, 2026, its CleanEffects whole-home air cleaner retailed for roughly $1,000 or more before installation and could cost several thousand dollars installed; Trane says its QuikBox or Slimfit filter may be a more cost-effective option. Your quote depends on the unit, your ductwork, the installation and the replacement filters.

Who should I call to test my indoor air quality?

It depends on what you suspect, because there is no single test for everything. For radon, Virginia law requires a tester listed by the National Radon Proficiency Program or National Radon Safety Board, or one meeting another approved proficiency measure, though a do-it-yourself kit is fine for screening. For stale air, humidity or dusty vents, call a licensed HVAC contractor. For hidden mold, hire an experienced mold professional.

Why does my house feel stuffy?

Usually because too little fresh air is getting in, the air is too humid, or air is not moving well through the ducts. A tight house with no mechanical ventilation, humidity above 50 to 60 percent, a clogged filter, closed vents or leaky ducts are the common causes. Check humidity, the filter and the exhaust fans first, and make sure your carbon monoxide alarms work.

What MERV rating filter should I use?

The EPA recommends at least MERV 13, or as high a rating as your system fan and filter slot can accommodate. Most home furnaces and HVAC systems can take a MERV 13 filter without problems if it is changed often. Buy the exact size printed on your old filter, make sure it fits snugly, and ask a technician if airflow drops after you upgrade.

Mini-Split Installation

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What does installing a mini-split involve?

A licensed HVAC contractor sizes the system with a load calculation, picks spots for the indoor and outdoor units, and gets your locality's permit. On the day, the crew mounts both units, runs refrigerant lines, power and a condensate drain through a small hole in the wall, then tests for leaks and checks the system before an inspector signs off. One room often takes a single day.

How much does it cost to install a mini-split in one room in Virginia?

A one-room, single-zone mini-split is the least expensive ductless setup, but the price turns on capacity, efficiency, the style of indoor unit, the line run and any electrical work, so compare itemized written quotes. The fixed pieces are small: King and Queen County's 2026 schedule lists $100 for a new HVAC system permit, and Appalachian Power offers a $300 rebate per qualifying unit bought through 2026.

Can I install a mini-split myself in Virginia?

Only partly. Virginia's contractor law exempts owners working on their own primary home, as long as they get the permits and pass inspection. The catch is federal: the EPA says connecting a mini-split's refrigerant lines, even pre-charged ones, requires Section 608 technician certification. For most owners that means hiring a licensed HVAC contractor for the job, or at least the refrigerant work.

Why is my new mini-split not heating or cooling well?

Start with the remote: the wrong mode, Auto mode, a timer or a set point too close to room temperature explains a lot. In winter, short cold spells of air are often a normal defrost cycle. If settings and clean filters do not fix it, the cause is usually sizing, placement or the refrigerant charge, and a new system goes back to its installer.

How long does a ductless mini-split last?

Plan on roughly 10 to 15 years, the range Carrier gives for a well-maintained, quality system, with 20 years or more possible. Trane cites a wider 15 to 30 years. Where yours lands depends on how well it was sized and installed, regular filter cleaning, professional service once or twice a year, and how hard the climate and daily use work it.

Mini-Splits

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How does a ductless mini-split work?

A ductless mini-split is a heat pump in two parts: an outdoor unit and one or more indoor units mounted on a wall or ceiling, joined by refrigerant lines that pass through a small hole in the wall. Refrigerant carries heat out of the room in summer and brings heat in from outdoors in winter, so each room is heated and cooled without ductwork.

How much does a ductless mini-split cost in Virginia?

It depends mostly on how many rooms you want to heat and cool. A single-zone system with one indoor unit costs the least; each extra indoor unit, a longer line set, a ceiling cassette or electrical work adds to it. Permit fees are set locally: Spotsylvania County's 2025 form lists $147.00 for a new HVAC unit in an existing house. Compare itemized written quotes.

Is a mini-split worth it for an addition or a garage?

Often, yes. ENERGY STAR lists additions and outbuildings such as garages, where extending ductwork is difficult, among the places mini-splits are increasingly used. It pays off most when the space is insulated, used regularly and sized with a load calculation. In Virginia the installer needs an HVAC contractor's licence, and a new system needs a permit from your locality.

Why is my mini-split leaking water inside?

Water dripping from the indoor unit usually means condensation is not draining: a clogged condensate line, a cracked or rusted drain pan, a unit mounted without the right slope, or a coil that froze because of dirty filters or low refrigerant and is now melting. Turn the unit off, catch the water and call a licensed HVAC technician.

How often should a mini-split be cleaned?

Clean the washable filters in each indoor unit on the schedule in your owner's manual: Trane says that can be every two weeks in peak heating or cooling season, Carrier says every four to six weeks. Then have a licensed HVAC technician clean and check the whole system at least once a year, or twice a year for a heat pump that heats and cools.

System Installation

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What does installing a new HVAC system involve?

A new HVAC system is a design job before it is an installation. A licensed contractor measures your house and calculates the heating and cooling load, picks matched equipment, checks and seals the ducts, pulls any permit your locality requires, installs the equipment, then sets the refrigerant charge and airflow to the manufacturer's specifications and has the work inspected.

How much does a new HVAC system cost in Virginia?

There is no single Virginia price. When we checked on October 26, 2026, Trane's 2026 national guide put its installed central air conditioners at $6,568 to $13,669 and its standard heat pump line at $8,313 to $15,608. Your quote depends on the system type, the size your house needs, efficiency, the ductwork, electrical changes and the permit, so get several itemized written quotes.

Do you need a permit to replace an HVAC system in Virginia?

Often, yes. Virginia's building code requires a permit for mechanical work but, for the residential groups it lists, exempts replacing appliances not fueled by gas or oil, so a gas or oil furnace swap needs one. Counties read the exemption differently: Pittsylvania County needs no permit for the same type, size and location, while Fairfax County's mechanical permit page lists HVAC replacement as needing one. Ask your building department.

Why is my new HVAC system not keeping up?

In extreme weather, long run times can be normal: Bryant says an air conditioner can typically cool about 20°F below the outdoor temperature. If it struggles in ordinary weather, the usual causes are wrong sizing, an incorrect refrigerant charge, low airflow, leaky or undersized ducts, or thermostat and backup-heat settings. Ask the installer to come back and measure, under any workmanship warranty in your contract.

How long does an HVAC system last?

Manufacturers' own estimates put central air conditioners at roughly 10 to 20 years, air-source heat pumps at about 10 to 15 and standard furnaces at about 15 to 20. Installation quality, correct sizing, yearly maintenance, clean filters and how hard the climate works the system decide where yours lands. ENERGY STAR suggests considering replacement after 10 years for a heat pump or air conditioner and 15 for a furnace.

Thermostat Installation

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How do I replace a thermostat?

If your thermostat is a standard low-voltage (24-volt) model, turn off the system's power, photograph and label each wire by its terminal letter, move each one to the matching terminal on the new base, then restore power and run setup. Stop if the old thermostat is marked 120 or 240 volts, you have a heat pump with a furnace, or the new one needs a C wire you lack.

How much does an HVAC company charge to install a thermostat in Virginia?

Each company sets its own price, so what you pay comes down to the visit, the labour and the thermostat itself. A straight swap on existing low-voltage wiring is the simple end; a missing C wire, a new wire run, a heat pump with a furnace or a line-voltage system all add work. Get a written quote and check your utility's thermostat rebate first.

Can a homeowner replace a thermostat in Virginia without a license?

Yes, in your own home. Virginia's contractor licensing law does not apply to work on a primary residence you own and live in, and its tradesman licence covers HVAC work done for the public for pay. A standard low-voltage thermostat also needs no permit. The building code still applies, and a line-voltage thermostat is electrical work best left to a licensed pro.

Why is my new thermostat not working?

Start with power: a breaker or the furnace switch left off, or a furnace door not fully closed, keeps the system from running. Then check for a built-in compressor delay, the wrong mode or system type in setup, a wire in the wrong terminal or the wrong R-wire setting, and a smart thermostat that needs a C wire.

Thermostats

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How do I program a thermostat to save money?

Program a comfortable temperature for when you are home and awake, around 68°F in winter, and let the thermostat drop it 7 to 10 degrees while you sleep or are out; in summer, let it run warmer while nobody is home. The Department of Energy put savings at up to 10% a year. Heat pumps do better on a moderate, steady heating setting unless the thermostat is made for them.

How much does it cost to replace a thermostat in Virginia?

The total is the thermostat plus any labour. When we checked on 26 October 2026, ecobee listed its basic smart thermostat at $139.99 and a power adapter for homes without a C wire at $24.99, and Columbia Gas of Virginia offered a $50 rebate to customers with primary natural gas heat. Installation has no set Virginia price; it rises with missing wires, heat pumps and line-voltage heat.

Should I hire an HVAC technician to replace my thermostat?

Not always. Swapping a standard 24-volt thermostat on a simple furnace and air conditioner is a job manufacturers write homeowner guides for, and Virginia does not require a permit application for it. Hire a licensed HVAC technician when there is no C wire or you have a heat pump, dual fuel, zoning or a humidifier, and leave a line-voltage thermostat to a licensed professional.

Why is my thermostat not turning on the heat?

Most often it is a setting or a power problem: the thermostat is not in Heat mode, the setpoint is not above room temperature, the batteries are weak, it is in a five-minute protection delay, or the furnace breaker, power switch or door is off or open. If the display says the heat is on and nothing runs, the fault is in the heating equipment.