Common HVAC & Plumbing Terms Explained

If you’ve ever searched for heating, cooling, or plumbing help and felt overwhelmed by the technical terms—don’t worry, you’re not alone. The world of home comfort can sound like a different language! To make things simpler, we’ve created this easy-to-browse ARS® HVAC & Plumbing Glossary to explain common terms, system components, and service processes in plain English. Each definition includes helpful links to related topics and services, so you can understand your home’s systems and make confident decisions about maintenance, repairs, and upgrades. Go ahead and bookmark this page—it’s a handy reference for whenever you need it.

 

Table of Contents

 

HVAC Basics & System Types

  • HVAC: HVAC stands for Heating, Ventilation, and Air Conditioning—the integrated system responsible for controlling temperature, airflow, and indoor air quality in your home or business. A typical HVAC system includes components such as a furnace or heat pump, an air conditioner, ductwork, thermostats, and filtration devices. Together, these elements maintain comfort while managing humidity and energy efficiency. Understanding how HVAC systems work helps homeowners identify when maintenance or upgrades are needed. 

  • Air Handler: An air handler is the indoor component of a central HVAC system that circulates air through ductwork. It houses the blower motor, evaporator coil, and air filter, and connects to both heating and cooling equipment. The air handler’s job is to push conditioned air throughout your home while pulling return air back for re-conditioning. If your air handler’s motor or coil fails, airflow and comfort can quickly suffer. 

  • Condenser (Outdoor Unit): The condenser—also called the outdoor unit—is part of your air conditioning or heat pump system. It releases heat collected from indoors into the outdoor air through refrigerant compression and condensation. Inside the condenser are the compressor, fan, and coil. When this unit becomes dirty or the fan motor fails, your cooling efficiency drops significantly. Regular cleaning and coil inspection keep your condenser performing effectively. 

  • Evaporator Coil: The evaporator coil is the indoor component where refrigerant absorbs heat from the air. As warm air passes over the coil, the refrigerant evaporates, cooling the air before it circulates through your ducts. A frozen or dirty coil can stop your system from cooling and lead to compressor damage. Maintaining clean filters and regular coil service helps prevent freeze-ups.

  • Heat Pump: A heat pump provides both heating and cooling by transferring heat instead of generating it. In summer, it moves heat outdoors to cool your home; in winter, it reverses direction to bring warmth inside. Modern heat pumps are extremely efficient in moderate climates and can reduce electricity or gas usage compared to traditional systems. Some models include variable-speed compressors for precise comfort and energy savings. 

  • Furnace (Gas/Electric): A furnace is the heating core of most HVAC systems, generating warm air and distributing it through ducts using a blower fan. Gas furnaces burn natural gas or propane, while electric furnaces use heating elements. Furnaces are rated by AFUE (Annual Fuel Utilization Efficiency), which measures how effectively fuel is converted into heat. Regular maintenance ensures safe combustion, high efficiency, and long lifespan.

  • Split System: A split system is a common type of HVAC setup that separates the indoor and outdoor components of heating and cooling. The indoor unit (air handler or furnace with evaporator coil) manages air circulation and temperature control, while the outdoor unit (condenser or heat pump) releases or absorbs heat. The two units are connected by refrigerant lines and electrical wiring. Split systems are popular for their efficiency, flexibility, and ability to provide consistent comfort throughout the home.

  • Mini-Split (Ductless): A mini-split, or ductless heat pump, provides zoned heating and cooling without traditional ductwork. Each indoor air handler connects to an outdoor compressor, allowing for personalized temperature control in individual rooms or zones. Mini-splits are ideal for additions, older homes, or spaces where installing ducts isn’t practical. Their high efficiency and quiet operation make them a popular upgrade option. 

  • SEER2 / HSPF2 / AFUE: These are standardized efficiency metrics used to compare HVAC systems: SEER2 (Seasonal Energy Efficiency Ratio 2) measures cooling efficiency for air conditioners and heat pumps; HSPF2 (Heating Seasonal Performance Factor 2) measures heating efficiency for heat pumps; and AFUE (Annual Fuel Utilization Efficiency) measures how much of a furnace’s fuel is converted into usable heat. Higher ratings mean lower energy use and utility bills.

  • Load Calculation (Manual J): A Manual J Load Calculation is the engineering process used to determine the precise heating and cooling capacity a home requires. It factors in square footage, insulation, window quality, climate zone, and air leakage to ensure your HVAC system is correctly sized. Oversized or undersized systems waste energy and reduce comfort. Professional installers perform Manual J calculations before recommending new equipment.

 

Air Conditioning (Cooling)

  • AC Tune-Up: An AC tune-up is a seasonal service that includes inspecting, cleaning, and testing your cooling system to ensure peak performance. During a tune-up, a technician checks refrigerant levels, electrical connections, coils, capacitors, and thermostat calibration. Regular tune-ups improve energy efficiency, prevent costly breakdowns, and extend equipment life—especially before high-use summer months.

  • Refrigerant (R-410A, R-454B): Refrigerant is the chemical compound that absorbs and releases heat in an HVAC system, enabling both cooling and heating cycles. Common types include R-410A, used in most systems built since 2010, and newer, low-GWP options like R-454B. Low refrigerant charge, often caused by leaks, reduces efficiency and can damage the compressor. Regular system inspections ensure safe and optimal refrigerant levels.

  • TXV / Expansion Device: A TXV—or expansion device—regulates how much refrigerant flows into the evaporator coil, maintaining proper pressure and temperature for efficient heat transfer. A malfunctioning TXV can cause poor cooling, coil freeze-ups, or compressor strain. It’s a key diagnostic checkpoint during professional tune-ups. 

  • Short Cycling: Short cycling occurs when an HVAC system repeatedly starts and stops within short intervals. This can result from oversized equipment, clogged filters, thermostat errors, or low refrigerant. Frequent cycling increases wear, energy use, and comfort imbalance. Proper sizing (via Manual J) and maintenance resolve most causes. 

  • Hard Start / Capacitor: A hard start occurs when an AC compressor struggles to turn on, often due to a failing capacitor or electrical imbalance. The capacitor stores and releases energy to start the compressor motor. Replacing a weak capacitor is a simple, low-cost fix that prevents compressor failure and restores reliable startup. 

  • Superheat / Subcool: Superheat and subcool are temperature measurements technicians use to verify refrigerant charge and system performance. Superheat measures how much heat refrigerant vapor gains after leaving the evaporator, while Subcool measures how much heat liquid refrigerant loses before expansion. Correct readings indicate healthy charge and airflow.

  • Two-Stage / Variable-Speed: Two-stage and variable-speed systems use advanced compressors and motors to adjust output based on demand. Two-stage systems run at low or high power, while variable-speed models continuously modulate for precise temperature and humidity control. These features improve comfort, air quality, and energy efficiency. 

  • Condensate Drain / Pan: As air cools, moisture condenses on the evaporator coil and drains into a condensate pan and pipe. If the drain clogs, water can back up, triggering float switches or leaks near the indoor unit. Regular drain cleaning prevents overflow and mold growth.

 

Heating (Furnaces & Coils)

  • AFUE (Annual Fuel Utilization Efficiency): AFUE measures how efficiently a furnace converts fuel into usable heat. For example, a 95% AFUE furnace converts 95% of its fuel into heat, losing only 5% through exhaust. High-efficiency furnaces (90%+) reduce energy costs and qualify for rebates. 

  • Heat Exchanger: The heat exchanger is the furnace component that transfers heat from combustion gases to the air. Cracks in a heat exchanger can leak carbon monoxide, posing safety risks. Routine inspections help ensure safe operation, preventing exposure and costly furnace repair service. 

  • Igniter / Flame Sensor: The igniter lights the burner in a gas furnace, while the flame sensor ensures a safe, consistent flame. Dirty or failed sensors commonly cause “no heat” calls in winter. Cleaning or replacing these parts restores reliable startup. 

  • Gas Valve / Draft Inducer: The gas valve controls fuel flow to the burners, and the draft inducer motor clears exhaust gases to maintain proper combustion. Malfunctioning components may cause ignition failure or unsafe venting. Professional testing ensures safety compliance.

  • Aux Heat (Heat Pump): Auxiliary or “backup” heat provides extra warmth when outdoor temperatures drop below a heat pump’s efficient range. It often uses electric resistance coils or a gas furnace in hybrid systems. Frequent aux-heat use can indicate thermostat or system sizing issues.

 

Indoor Air Quality (IAQ)

  • MERV / HEPA (Air Filters): MERV (Minimum Efficiency Reporting Value) rates how effectively filters capture airborne particles; higher MERV values trap finer pollutants. HEPA filters remove 99.97% of particles ≥0.3 microns and are used in high-IAQ environments. Proper filtration improves air quality and HVAC longevity.

  • Humidity (Dehumidifier/Humidifier): Maintaining indoor humidity between 30–50% prevents mold growth, static, and dryness. Whole-home humidifiers add moisture during heating seasons, while dehumidifiers remove excess humidity in summer. Balanced humidity improves comfort and system efficiency. 

  • UV-C / Air Purifier: UV-C lights and advanced air purifiers reduce mold, bacteria, and allergens circulating through HVAC systems. Installed near the coil or return air, they help prevent microbial growth and maintain clean airflow.

  • HRV/ERV (Ventilation Systems): HRV (Heat Recovery Ventilator) and ERV (Energy Recovery Ventilator) systems exchange stale indoor air with fresh outdoor air while recovering heat (and moisture, in ERVs). These ventilation systems improve indoor air quality and energy efficiency, especially in tight homes.

  • Negative Pressure / Infiltration: Negative pressure occurs when exhaust fans or leaks pull unconditioned outdoor air into your home. This can cause drafts, humidity issues, or poor air balance. Proper duct sealing and ventilation balance prevent these problems. 

 

Ductwork & Airflow

  • Static Pressure: Static pressure is the air resistance inside your duct system—essentially its “blood pressure.” High static pressure reduces airflow, efficiency, and comfort. Regular duct and vent cleaning, inspections, and filter changes maintain proper pressure balance. 

  • Return vs. Supply Air: Return air is drawn from rooms back into the HVAC system for re-conditioning, while supply air is newly heated or cooled air delivered through vents. Balanced return and supply airflow ensures even comfort and efficient operation. 

  • Zoning: A zoned HVAC system divides your home into independent comfort areas, each with its own thermostat and motorized dampers. This setup reduces energy waste and solves hot/cold spot issues in multi-level homes. 

  • Duct Leakage / Aeroseal: Leaky ducts waste up to 30% of conditioned air, raising bills and reducing comfort. Sealing ducts—especially with Aeroseal technology—boosts efficiency and improves air quality.

  • Registers / Grilles / Diffusers: Registers and diffusers deliver conditioned air, while grilles allow air return. Adjusting or cleaning them helps balance comfort and airflow.

 

Thermostats & Controls

  • Smart Thermostat: A smart thermostat is a Wi-Fi–enabled control that automatically adjusts heating and cooling based on schedules, occupancy, or learning algorithms. Many models integrate with mobile apps and smart assistants for remote management and energy reporting. Installing a smart thermostat can lower energy bills and improve comfort consistency across zones. 

  • C-Wire (Common Wire): The C-wire supplies continuous 24-volt power from your HVAC system to advanced smart thermostats. Without it, some thermostats can lose connection or drain batteries quickly. An HVAC technician can add or rewire a C-wire to ensure stable thermostat performance. 

  • Heat Pump Thermostat Settings: Heat pump thermostats are programmed to manage both heating and cooling stages efficiently, using sensors to control when auxiliary heat engages. Proper staging and balance-point settings prevent energy waste in cold weather. 

  • Emergency Heat Mode: Emergency Heat Mode is a manual setting on heat pumps that activates backup heating—usually electric coils or a gas furnace—when the outdoor unit isn’t functioning. Emergency heating should only be used temporarily until repairs are made, as it consumes more energy. 

  • Setback / Scheduling: Setback scheduling lowers heating or cooling output automatically during unoccupied hours. Smart thermostats can adjust based on routines or geofencing, balancing comfort and energy savings. Even small daily setbacks can reduce annual energy costs by 10–15%. 

 

Energy, Ratings & Rebates

  • SEER2 / EER2 (Cooling Efficiency Ratings): SEER2 (Seasonal Energy Efficiency Ratio 2) and EER2 (Energy Efficiency Ratio 2) are updated 2023 standards measuring AC and heat pump efficiency under more realistic testing conditions. Higher numbers mean greater efficiency and lower energy use. 

  • HSPF2 (Heating Efficiency Rating): HSPF2 (Heating Seasonal Performance Factor 2) measures how efficiently a heat pump provides heating over a season. A higher HSPF2 means the unit delivers more heat per unit of electricity consumed.

  • ENERGY STAR® Certification: ENERGY STAR® is an EPA-backed program certifying products that meet strict energy-efficiency criteria. HVAC systems with this label use 10–20% less energy and may qualify for tax credits or rebates. 

  • Duct Design (Manual D): Manual D design specifies HVAC ductwork sizing and layout for optimal airflow and efficiency. Properly designed ducts ensure quiet operation, balanced temperatures, and reduced strain on HVAC equipment. 

  • Thermal Envelope: The thermal envelope is the barrier that separates conditioned indoor air from outdoor air—made up of insulation, windows, doors, and air sealing. A tight envelope reduces energy loss and helps your HVAC system run more efficiently. 

 

Plumbing Basics

  • Potable vs. Non-Potable Water: Potable water is safe for drinking and cooking, while non-potable water is for non-consumption uses like irrigation or reclaimed systems. Understanding which water lines are which prevents cross-contamination and safety issues. 

  • Shut-Off Valve / Main Valve: A shut-off valve stops water flow to a fixture or the entire property. Knowing where your main valve is located allows quick response during leaks or emergencies. 

  • Water Pressure (PSI): Residential water pressure should range between 40 and 60 PSI. Excessive pressure strains fixtures and appliances, while low pressure indicates possible leaks or sediment buildup. A pressure-reducing valve (PRV) keeps flow balanced and safe. 

  • Water Hammer / Arrestor: Water hammer is a banging sound in pipes caused by sudden valve closures. Installing water-hammer arrestors absorbs shock and protects plumbing joints from damage. 

  • PEX / Copper / PVC / CPVC (Piping Materials): Common piping materials include PEX (flexible plastic used in modern homes), Copper (durable & heat-resistant), and PVC/CPVC (cost-effective for drains & hot water). Each offers different benefits for longevity, cost, and installation speed. 

  • Backflow / RPZ Device: A backflow preventer or RPZ (Reduced Pressure Zone) valve stops contaminated water from flowing back into your drinking supply. Many cities require annual testing by licensed plumbers to ensure compliance.

  • Soldering / Press Fittings: Soldering joins copper pipes using melted metal alloy, while press-fit systems use compression rings for faster, flame-free installation. Both methods create watertight seals when done correctly.

 

Water Heaters (Tank & Tankless)

  • Tank Water Heater (Gas/Electric): A tank water heater stores and heats a set volume of water using gas burners or electric elements. It relies on an anode rod to prevent corrosion and typically lasts 8–12 years. 

  • Tankless (On-Demand Water Heater): Tankless water heaters heat water only when needed, providing endless hot water and higher efficiency. Annual descaling keeps the heat exchanger clean for peak performance. 

  • First Hour Rating / GPM (Capacity Metrics): The First Hour Rating (FHR) indicates how much hot water a tank heater can deliver in one hour, while GPM (Gallons Per Minute) measures tankless output. These ratings help homeowners choose systems sized for family usage. 

  • Temperature and Pressure (T&P) Relief Valve: The temperature and pressure relief valve (T&P) is a critical safety device that releases pressure if a water heater overheats. Routine testing prevents dangerous tank pressure buildup. 

  • Recirculation Pump: A recirculation pump moves hot water through pipes so faucets deliver heat instantly, saving water waste. Many modern pumps use sensors or timers for efficiency. 

 

Drains, Sewers & Fixtures

  • P-Trap / S-Trap: A P-trap or S-trap is a curved section of drainpipe that holds water to form a seal against sewer gas entering your home. The “P” shape is standard in modern plumbing, while “S” traps are older and more prone to siphoning issues. Keeping the trap filled prevents odors, and periodic cleaning removes buildup that can block drainage. 

  • Cleanout: A cleanout is a capped access point in your plumbing or sewer line that allows plumbers to insert augers, cables, or cameras for maintenance and inspections. Cleanouts make diagnosing clogs and sewer issues faster and less invasive. Homeowners should know where theirs is located for easier emergency access. 

  • Sewer Camera Inspection: A sewer camera inspection uses a waterproof camera attached to a flexible cable to view the inside of drain and sewer lines. It identifies common issues like root intrusion, pipe sagging, cracks, and blockages—pinpointing repair needs without digging. This technology saves time and reduces unnecessary excavation. 

  • Hydro Jetting vs. Cabling: Hydro jetting uses high-pressure water to scour grease, roots, and buildup from pipes, while cabling (snaking) relies on a rotating steel cable with cutting heads to break through clogs. Jetting is ideal for heavy or recurring blockages, while cabling handles minor or localized clogs. Many drain cleaning professionals use both methods for thorough results. 

  • Sump Pump / Ejector Pump: A sump pump removes groundwater collected in a basin beneath your basement or crawl space, preventing flooding. An ejector pump performs a similar function for wastewater, lifting sewage from lower levels up to the main drain line. Both are vital for homes below street grade or in flood-prone areas. 

  • Wax Ring / Closet Flange: The wax ring creates a watertight seal between the toilet and the closet flange, which anchors the toilet to the floor and connects it to the drain. Over time, wax rings can dry out or compress, leading to leaks and unpleasant odors. Replacing the seal is a quick, affordable fix that prevents damage to flooring and subfloors. 

  • Garbage Disposal (HP ratings): A garbage disposal grinds food waste into small particles that can safely pass through household plumbing. Disposals are rated by horsepower (HP)—from ⅓ HP for light use to 1 HP + for heavy-duty performance. Modern units feature jam-resistant impellers, overload protection, and manual reset buttons to extend lifespan. 

 

Water Quality, Treatment & Leaks

  • Hardness (GPG) / Water Softener: Hardness — measured in grains per gallon (GPG) — refers to dissolved minerals that cause scale. A water softener exchanges calcium and magnesium ions for sodium or potassium, protecting plumbing and appliances. 

  • Point-of-Use vs. Whole-Home Filtration: Point-of-use filters treat water at individual taps for drinking or cooking, while whole-home systems filter water for every fixture. The right setup depends on local water quality and household needs. 

  • Chloramines / Activated Carbon: Chloramines are disinfectants used in municipal water that can affect taste and degrade rubber plumbing parts. Activated carbon filters remove these compounds and many organic contaminants for cleaner, better-tasting water. 

  • Slab Leak: A slab leak occurs when a water line beneath a concrete foundation breaks, leading to high bills, warm spots, or mold. Professional acoustic and thermal tools locate leaks without major demolition. 

  • Leak Detection (Acoustic/Infrared): Leak detection uses specialized sensors to locate hidden plumbing leaks through sound (acoustic), temperature (thermal), or moisture mapping (infrared). Early detection prevents costly structural damage. 

 

Symptoms & Quick Diagnostics

Cooling & HVAC System Symptoms

  • AC Blowing Warm Air: When your air conditioner blows warm air, it may indicate restricted airflow, frozen coils, or low refrigerant levels. Cleaning filters, clearing coils, or recharging the system typically restores cool airflow and efficiency.

  • AC Freezing Up (Ice on Lines): Restricted airflow or low refrigerant causes coil icing, reducing cooling and straining the compressor. Turn off your system and let it thaw before scheduling service. 

  • Uneven Cooling (Hot & Cold Spots): Unbalanced duct design, zoning issues, or blocked vents can make rooms inconsistent. Adjust dampers or inspect ductwork for leaks. 

  • Strange Noises from AC Unit: Buzzing, rattling, or hissing sounds often point to loose components, refrigerant leaks, or worn fan motors. 

  • High Humidity Indoors: Excess humidity indoors may result from poor airflow, dirty coils, or an oversized air conditioner that short cycles before removing moisture. System recalibration or a whole-home dehumidifier restores balanced comfort. 

  • Weak Airflow from Vents: Low airflow typically means a clogged filter, duct obstruction, or failing blower motor. Cleaning filters and inspecting ductwork can improve circulation and overall efficiency. 

  • High Energy Bills (Heating or Cooling): Sudden energy spikes often indicate leaky ducts, worn insulation, or inefficient equipment. Sealing leaks and upgrading to high-efficiency systems lower utility costs and environmental impact. 

  • Thermostat Not Responding: If the thermostat doesn’t respond or hold settings, weak batteries, loose wiring, or Wi-Fi connectivity issues may be to blame. Replacing batteries or resetting the device usually restores communication. 

Heating & Furnace Symptoms

  • Furnace Blowing Cold Air: A furnace blowing cold air may result from ignition failure, a dirty flame sensor, or a tripped limit switch. Prompt repair restores safe, consistent heat and prevents further damage. 

  • Furnace Won’t Turn On: If your furnace doesn’t start, check the breaker, thermostat, and safety switch first. Persistent issues often involve a failed igniter, control board, or thermostat communication error requiring service. 

  • Furnace Runs Constantly: When a furnace runs without cycling off, it may signal restricted airflow from a dirty filter, a malfunctioning relay or thermostat, or an oversized system that heats too quickly and never balances temperatures. Continuous operation wastes energy and can shorten component lifespan. Regular filter changes and professional inspection help restore normal cycling and improve comfort efficiency. 

  • Burning Smell from Vents: A mild burning odor at the start of heating season is often dust burning off components. Lingering smells, however, can indicate wiring or motor issues that require immediate inspection. 

  • Noisy Furnace (Booming, Whining, or Rattling): Unusual furnace noises may result from delayed ignition, loose panels, or worn bearings. Addressing these early prevents safety hazards and expensive repairs. 

  • Pilot Light Keeps Going Out: Repeated pilot outages can be caused by drafts, dirty thermocouples, or failing gas valves. Cleaning or replacement ensures safe and consistent furnace ignition. 

Plumbing Symptoms

  • Low Water Pressure: Consistently low water pressure may point to a failing pressure-reducing valve, hidden leak, or mineral buildup. If it affects multiple fixtures, professional inspection of the main supply line is recommended. 

  • Gurgling Drains: Gurgling or slow drains usually indicate partial clogs or venting issues in the plumbing system. Cleaning traps or vent stacks restores normal flow and prevents backups. 

  • Slow Drains (Sink/Tub): Hair, grease, or soap scum buildup slows drainage. Avoid chemical cleaners; use mechanical methods like a drain snake or schedule a professional cleaning. 

  • Toilet Won’t Stop Running: A worn flapper, fill valve, or chain prevents the tank from sealing, causing constant refilling and water waste. Replacing these parts stops the leak and reduces utility costs. 

  • Foul Odor from Drains: Sewer-like odors stem from dry P-traps or organic buildup. Running water through seldom-used drains and cleaning traps eliminates smells and bacteria. 

  • Water Backing Up in Basement: Sewage or water backups often indicate a clogged main line or failed sump pump. Immediate professional service prevents flooding and contamination. 

  • Leaking Faucet or Showerhead: Dripping fixtures are usually caused by worn washers, O-rings, or cartridges. Quick repair stops waste and protects plumbing hardware. 

  • Noisy Pipes (Banging/Water Hammer): Sudden pipe banging occurs when valves close abruptly, creating hydraulic shock. Installing water-hammer arrestors or pressure regulators resolves the noise and protects pipes. 

Water Heater & Hot Water Issues

  • Water Heater Not Enough Hot Water: Insufficient hot water may result from sediment buildup, a damaged dip tube, or incorrect thermostat settings. Flushing or recalibration restores consistent performance. 

  • No Hot Water at All: Complete loss of hot water often stems from electrical failure, a tripped breaker, or a faulty gas valve or pilot. Professional service restores operation safely. 

  • Water Too Hot: Overheated water signals a misadjusted thermostat or stuck heating element. Resetting or replacing components eliminates scald risk. 

  • Water Leaking from Heater Base: Leaks at the tank’s base usually mean internal corrosion or a failed drain valve. Replacement is often the safest long-term solution. 

  • Discolored or Rusty Water: Rust-colored water indicates a corroded tank lining or failing anode rod. Replacing the rod can extend tank life and restore clarity. 

  • Smelly Hot Water (Rotten Egg Odor): A sulfur smell results from bacteria reacting with the anode rod. Flushing the tank and installing an aluminum-zinc rod removes odor and prevents recurrence. 

Indoor Air Quality & Comfort Issues

  • Mildew Smell from Vents: A musty or mildew odor from vents signals microbial growth or a clogged condensate drain. Cleaning coils and drain pans removes buildup and improves indoor air quality. 

  • Dust Around Vents or Home: Visible dust near vents often means ducts need cleaning or filters are missing or overdue for replacement. Regular filter changes reduce allergens and system strain. 

  • Dry Air in Winter: Low humidity during winter causes static, dry skin, and wood cracking. Whole-home humidifiers add moisture for healthier, more comfortable indoor air. 

  • Allergy or Asthma Flare-Ups Indoors: Poor filtration, mold, or airborne pollutants can trigger respiratory symptoms. Upgrading to HEPA-grade filters and maintaining clean ducts supports better breathing conditions. 

  • Thermostat Temperature Doesn’t Match Room: If displayed temperature differs from how the room feels, miscalibration or sensor placement may be at fault. Recalibration or relocation improves accuracy and comfort. 

Emergency & Red-Flag Conditions

  • System Tripping Breaker Repeatedly: Frequent breaker trips suggest overloaded circuits, shorted wiring, or failing motors. A licensed technician should inspect to prevent electrical hazards. 

  • Burning or Metallic Smell: A metallic or burning odor often signals electrical overheating or blower-motor failure. Shut down power immediately and request emergency service. 

  • Hissing or Bubbling Sound (AC Lines): Hissing sounds near refrigerant lines indicate a leak. Because refrigerants are regulated, only certified HVAC professionals should perform repairs. 

  • Water in Ceiling or Utility Closet: Water pooling near HVAC units or ceilings signals a clogged condensate line or burst pipe. Shut off the system and call for immediate service to prevent damage. 

  • Carbon Monoxide Alarm Going Off: If your CO alarm sounds, turn off gas appliances, ventilate the area, and evacuate immediately. Call 911 before contacting an HVAC technician to inspect for leaks. 

 

Maintenance, Plans & Safety

  • Preventive Maintenance: Preventive maintenance combines HVAC tune-ups and annual plumbing inspections to catch issues early. Regular care reduces breakdowns and improves HVAC system longevity. 

  • Filter Change Cadence: Air filters should be replaced every one to three months based on filter type, pets, and dust levels. Consistent replacement protects equipment and maintains air quality. 

  • Anode Rod Replacement: The anode rod protects the water-heater tank from corrosion by sacrificing itself to rust first. Replacing it every few years extends tank life and prevents leaks. 

  • Flush & Descale (Tankless): Tankless water heaters require annual flushing with vinegar or descaling solution to remove mineral buildup. This preserves heating efficiency and performance. 

  • CO Alarm / Gas Leak Protocol: Carbon-monoxide detectors warn of dangerous gas buildup. If you smell gas or your alarm sounds, evacuate immediately and contact emergency services before calling a technician. 

 

Permits, Codes & Certifications

  • Permit (HVAC/Water Heater Replacement): Replacing or altering fuel-burning or vented equipment often requires a municipal permit and inspection to ensure code compliance. 

  • Licensed, Bonded, Insured: These credentials confirm a contractor meets state and financial requirements, protecting homeowners from liability and ensuring professional workmanship. 

  • NATE-Certified Technician: NATE (North American Technician Excellence) certification represents advanced HVAC knowledge and proven field experience. ARS® technicians maintain this credential for dependable, expert service. 

  • Backflow Testing: Many municipalities require annual backflow testing to prevent water supply contamination. Certified plumbers verify device performance and submit documentation to local authorities. 

 

Financing, Guarantees & Scheduling

  • Exceptional Service Guarantee®: ARS® backs every repair and installation with our Exceptional Service Guarantee®, ensuring your satisfaction with every visit. If you’re not happy, we’ll make it right—guaranteed. 

  • Manufacturer vs. Labor Warranty: A manufacturer warranty covers parts defects, while a labor warranty covers installation workmanship. Understanding both helps homeowners plan maintenance and avoid unexpected costs. 

  • 0%/Low-APR Options: ARS® offers flexible financing for new systems, including 0% and low-APR promotions (subject to credit approval). Financing allows comfort upgrades without large upfront costs. 

  • Emergency Service (24/7): Emergency service covers urgent issues such as no heat, major leaks, or unsafe conditions. ARS® dispatches licensed technicians 24/7 for fast, reliable repairs. 

  • Online Scheduling: Our online scheduling tool makes it easy to book HVAC or plumbing appointments anytime. Enter your ZIP code to connect with your nearest ARS® branch and choose a time that works for you.