Frequently Asked HVAC Questions

Straightforward Answers From Your Local HVAC Experts

At AirTech, we believe homeowners should understand their heating and cooling systems before making a repair or replacement decision. Below are answers to some of the most common HVAC questions our technicians receive from homeowners throughout Pasadena, the San Gabriel Valley, and surrounding Southern California communities.

HVAC Installation & Warranty Questions

Why should I hire a licensed HVAC contractor instead of a handyman?

Heating and air conditioning systems involve high-voltage electrical components, refrigerants, gas lines, drainage, airflow requirements, and California building and safety codes. Proper installation requires specialized HVAC training, tools, licensing, and experience.

Hiring an unlicensed handyman may save money upfront, but improper installation or repair can lead to poor comfort, higher utility bills, repeated breakdowns, safety issues, and premature equipment failure.

Manufacturer warranty requirements are another important reason to use a licensed HVAC contractor. Many major HVAC manufacturers require equipment to be properly installed by a licensed or qualified HVAC professional for warranty coverage. Manufacturers may also require proof of purchase, proof of installation, equipment registration, and an installing contractor’s invoice before approving warranty parts.

If equipment is improperly installed or the required installation documentation cannot be provided, warranty coverage may be reduced or denied depending on the manufacturer’s specific warranty terms.

At AirTech Air Conditioning & Heating, our systems are professionally installed by trained HVAC professionals, and we maintain the documentation necessary to help protect your manufacturer’s warranty and your investment.

How long does a new HVAC installation take?

Most residential HVAC replacement projects can be completed in approximately one to three days, depending on the type of system, accessibility, electrical requirements, and other conditions inside the home.

A straightforward furnace and air conditioner or heat pump replacement may take up to three days, while more complex systems can require additional time.

If AirTech is also replacing or modifying the home’s ductwork, the project may take approximately three to five days.

Before installation begins, we will review the scope of work with you so you know what to expect.

How should I prepare my home for an HVAC installation?

Before your installation appointment, we recommend:

Clearing a pathway to the indoor HVAC equipment
Clearing access around the outdoor condenser or heat pump
Moving fragile or valuable items away from the work areas
Securing pets in a separate room or safe area
Making sure technicians can easily access electrical panels, attics, closets, crawlspaces, or other areas included in the project

Preparing these areas ahead of time helps our installation team work safely and efficiently.

What happens if my new HVAC system has a problem after installation?

AirTech stands behind both our workmanship and the equipment we install.

If your new heating or cooling system experiences an installation-related problem or suspected equipment failure, contact us and we will schedule a technician to diagnose the issue.

Covered repairs will be handled according to the specific manufacturer’s parts warranty and AirTech labor warranty included with your installation.

Because warranty coverage varies by manufacturer, equipment, and installation package, we recommend reviewing the warranty information provided with your proposal.

Do I need proof that my HVAC system was professionally installed for a warranty claim?

In many cases, yes. HVAC manufacturers may require documentation showing that the equipment was purchased through an authorized source and professionally installed by a licensed or qualified HVAC contractor before approving warranty parts.

Depending on the manufacturer, you may be asked to provide:

The original purchase invoice
The installation invoice or contract
The installing contractor’s information
Equipment model and serial numbers
Warranty registration information
The installation date
Maintenance or service records

Keeping these records can make the warranty process much easier if a covered component fails in the future.

At AirTech Air Conditioning & Heating, we maintain detailed installation records for the systems we install so our customers have documentation available when a manufacturor warranty claim is needed.

Because warranty requirements vary by manufacturer and equipment, homeowners should always review the specific warranty terms provided with their HVAC system.

Understanding Your HVAC Equipment

Why is water leaking from my indoor AC unit?

One of the most common causes of water leaking from an indoor air conditioning unit is a clogged condensate drain line.

Air conditioners naturally remove moisture from the air. That water normally drains safely outside the home. Dirt, algae, sludge, or debris can clog the drain and cause water to back up into the drain pan or surrounding area.

Other possible causes include:

A cracked or damaged drain pan
A disconnected drain line
A dirty air filter restricting airflow
A frozen evaporator coil
Low refrigerant
Improper equipment installation or drainage

If you notice water around your furnace, air handler, or indoor AC equipment, turn the system off to prevent property damage and have the cause professionally diagnosed.

What is AC short cycling?

Short cycling occurs when an air conditioner or heat pump repeatedly turns on and off without completing a normal heating or cooling cycle.

Short cycling can increase energy consumption, create uneven temperatures, and place unnecessary wear on components such as the compressor.

Common causes can include:

A dirty air filter
Thermostat problems
Refrigerant issues
Dirty indoor or outdoor coils
Electrical or control problems
An oversized HVAC system
Restricted airflow

Because several different problems can cause short cycling, the system should be properly diagnosed rather than simply replacing parts.

How can I tell if my air ducts are leaking?

Common signs of leaking or damaged ductwork include:

Rooms that are difficult to heat or cool
Large temperature differences between rooms
Higher-than-normal heating or cooling bills
Weak airflow from certain registers
Excessive dust
Whistling, rattling, or unusual airflow noises
Visible disconnected, crushed, or damaged ducts

Duct leakage can allow conditioned air to escape into attics, crawlspaces, or other unconditioned areas instead of reaching your living space.

A professional duct inspection can determine whether your ductwork should be repaired, sealed, insulated, or replaced.

Should residential air ducts be professionally cleaned?

Air ducts do not necessarily need to be cleaned on a routine schedule. Whether duct cleaning is beneficial depends on the condition of the duct system and what has occurred inside the home.

Professional duct cleaning may be appropriate when there is:

Significant dust or debris inside the duct system
Visible contamination or suspected mold growth
Rodent or insect activity
Debris blowing from supply registers
Heavy construction or remodeling dust
Smoke, soot, or contamination following a nearby fire
Contamination following certain water or restoration events

Before paying for duct cleaning, it is important to determine whether the ducts actually need cleaning and whether there is an underlying problem, such as damaged ductwork, poor filtration, air leakage, or moisture, that should also be corrected.

Should I have my air ducts cleaned after a nearby wildfire or house fire?

Possibly. Homes located near a wildfire or structure fire can be exposed to smoke, soot, ash, and extremely fine airborne particles.

However, duct cleaning is not automatically necessary after every nearby fire. The HVAC system and ductwork should first be inspected to determine whether contamination entered the system.

Depending on the level of exposure, AirTech may recommend some combination of:

Replacing the HVAC filter
Inspecting the return and supply ductwork
Inspecting and cleaning the blower compartment
Inspecting the evaporator coil
Cleaning contaminated ductwork when appropriate
Checking for duct leaks that may have pulled smoke or ash into the system

If you continue to smell smoke when the HVAC system operates or see soot or debris around the registers, a professional inspection is recommended.

Can repairing or sealing my ductwork lower my energy bills?

Yes. Leaking ducts can waste a significant amount of the heating and cooling produced by your HVAC system, particularly when ducts run through an attic, crawlspace, garage, or other unconditioned area.

Repairing disconnected ducts and properly sealing and insulating ductwork can:

Reduce conditioned-air loss
Improve airflow
Reduce hot and cold spots
Improve comfort
Reduce unnecessary HVAC runtime
Help lower heating and cooling costs

The actual savings will depend on how much leakage exists and where the ductwork is located.

How long does a furnace typically last?

A properly installed and maintained furnace can commonly last approximately 15 to 20 years, although actual equipment life varies considerably.

Factors that affect furnace life include:

How often the system operates
Maintenance history
Installation quality
Airflow and duct conditions
Filter replacement
Climate
Equipment quality
Previous repairs

Age alone does not mean a furnace has to be replaced. However, if a furnace is approaching 15 to 20 years old and begins requiring expensive repairs, it is usually a good time to compare the cost of repairing the existing system with replacing it.

Why does my furnace smell like it’s burning when I first turn it on?

A mild burning-dust smell when a furnace is first used after sitting unused for several months can be normal.

Dust can settle on components during the warmer months and briefly produce an odor when the heating system operates for the first time. The smell should normally disappear fairly quickly.

However, shut the system off and contact a professional immediately if you notice:

A strong electrical or melting-plastic smell
Persistent smoke
A strong gas odor
A rotten-egg or sulfur-type odor
An odor that continues or becomes stronger

Unusual or persistent odors should never be ignored.

HVAC Maintenance & System Care

How often should I change my HVAC air filter?

The correct filter replacement schedule depends on the filter, HVAC system, household, and how frequently the equipment operates.

For many homes using a standard 1-inch HVAC filter, we recommend checking the filter monthly and replacing it approximately every one to three months as needed.

Larger high-capacity media filters, including some 4- or 5-inch filters, may last approximately six to twelve months, although they should still be inspected periodically.

You may need to replace filters more frequently if you have:

Multiple pets
Heavy HVAC usage
Construction or remodeling dust
A large household
High levels of indoor dust
Family members sensitive to airborne particles

Never rely only on the calendar. Check the actual condition of the filter.

What thermostat temperature should I use to save energy?

There is not one perfect thermostat setting for every homeowner.

In general, the closer your indoor temperature is to the outdoor temperature, the less energy your HVAC system will use.

Common energy-saving starting points are around 78°F during warmer weather and 68°F during cooler weather, but comfort, humidity, occupancy, health considerations, equipment type, and utility rates should all be considered.

A programmable or smart thermostat can also reduce energy use by automatically adjusting temperatures when you are sleeping or away from home.

For heat pump systems, large temperature setbacks may not always provide the same benefits as they do with traditional furnaces, so thermostat strategy should match the type of HVAC equipment installed.

How often should my HVAC system be serviced?

At AirTech, we recommend professional HVAC maintenance twice per year:

Cooling-system maintenance before or during the cooling season
Heating-system maintenance before or during the heating season

Regular HVAC maintenance can help identify problems early, maintain proper airflow, improve system reliability, and reduce the likelihood of unexpected breakdowns.

Maintenance is especially important in Southern California because air conditioning and heat pump systems can operate for long periods during hot weather.

What is included in AirTech’s HVAC maintenance membership?

Our maintenance membership is designed to make routine HVAC maintenance simple.

For $200 per year, membership includes two maintenance visits annually and an exclusive 10% discount on qualifying future HVAC repairs.

Regular maintenance also creates a documented service history for your heating and cooling equipment, which can be helpful if a manufacturor warranty claim is ever necessary.

Contact AirTech for current membership terms, exclusions, and coverage details.

Is HVAC maintenance required to keep my manufacturer’s warranty?

Warranty requirements vary by manufacturer and equipment.

Most manufacturers expect homeowners to properly maintain their HVAC equipment, and lack of maintenance or damage caused by neglect may affect whether a particular failure is covered.

Manufacturers may also request maintenance or service records when reviewing certain warranty claims.

For that reason, AirTech recommends keeping copies of your HVAC maintenance and repair records throughout the life of your equipment.

Our maintenance program makes it easier to maintain a documented history of professional HVAC service.

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HVAC Repair & Replacement Questions

Should I repair my old HVAC system or replace it?

There is no single age or repair price that automatically means an HVAC system should be replaced.

When helping homeowners decide whether to repair or replace a system, we consider:

Age of the equipment
Cost of the repair
Overall system condition
Repair history
Refrigerant type
Energy efficiency
Indoor comfort
Availability of replacement parts
Manufacturer warranty coverage
Expected remaining equipment life

For equipment 10 years old or older, a major repair is a good reason to compare both options before spending money.

At AirTech, we can provide repair and replacement options so you can compare the costs and make the decision that makes the most sense for your home and budget.

Will a new HVAC system lower my utility bills?

It can, especially when replacing older or inefficient equipment, but the amount of savings varies from home to home.

Energy usage is affected by much more than the efficiency rating printed on the HVAC equipment. Other important factors include:

Proper equipment sizing
Duct leakage
Insulation
Windows
Thermostat settings
Installation quality
Outdoor temperatures
Utility rates
How frequently the system operates

The best HVAC system is not simply the equipment with the highest efficiency rating. It should be properly sized, properly installed, and matched to the home’s ductwork and comfort requirements.

Please be advised that when converting your current gas system to an all-electric heat pump system:

It will take longer to heat the home and/or space, and the temperatures coming out of the supply vents will not be as hot.
It runs off electricity instead of gas so your gas bill will decrease but your electric bill will increase therefore it might cost a lot more to run your heat compared to a gas system.
The outdoor condenser will run when in heating mode.

Do you offer HVAC financing?

We do! You can visit our Financing Page to learn more!

How much does HVAC service cost?

We believe homeowners should have access to straightforward information about HVAC pricing.

The cost of HVAC service depends on the type of service, equipment, diagnosis, parts required, and scope of work.

You can view our current service pricing here.

If additional repairs are recommended after diagnosing your system, our technician will explain the problem and provide pricing before proceeding with the repair.

Still Have Questions About Your HVAC System?

Every home and HVAC system is different, and sometimes the best way to get an answer is to have an experienced professional take a closer look. Whether you need a repair, routine maintenance, or help deciding if it’s time to replace your system, AirTech is here to help homeowners throughout Pasadena and the San Gabriel Valley make informed decisions about their home comfort.

Have an HVAC question or need service? Contact AirTech today to schedule an appointment with our team.