If you have questions regarding heating, cooling, financing, or are looking to know more about our services at Mark Hill Heating & Air, check out our frequently asked questions below! If you have an additional question, feel free to give us a call or contact us online!

Air Conditioning

Why do I need to add refrigerant to my system?

You should not need to regularly add refrigerant to your system. Air conditioning systems do not use up refrigerant like a car uses gas. If your system is low on refrigerant it means that it has leaked out or was not charged correctly to begin with.

How do I know what refrigerant my AC uses?

There should be a label on your air conditioner close to the model number.

What is R-22 and why is it being phased out?

R-22 is a refrigerant that was used in most residential air conditioning units prior to 2010.  It has been determined that R-22 depletes the ozone layer and so it has been scheduled by the EPA to be phased out.  On January 1, 2010 manufacturers were banned from manufacturing equipment containing R-22. R-22 is still produced to service existing equipment, but is tightly controlled by the EPA. On January 1, 2020 chemical manufacturers will no longer be able to produce R-22 to service existing air conditioners.

What is Freon?

“Freon” is the brand name of a refrigerant. It is often used generically just like “Kleenex” is often used to refer to any brand of tissue.

Do I need to replace my line set and indoor coil?

This can depend on the age of your system, the refrigerant it uses and the size of refrigerant lines required for the new air conditioner.

What is involved in replacing my air conditioner?

It depends on individual circumstances. It can be as simple as replacing the outside unit, or could require replacement of the indoor coil and furnace as well.

Should I repair or replace my air conditioner?

Your air conditioner is a personal preference and an investment, so the final decision is yours concerning repairing or replacing your system. Our job is to give you detailed, honest information about the costs and benefits of your various options. At Mark Hill Heating & Air, we take this part of our job very seriously. Whatever option you choose, we want to be your heat and air service provider for life. We’ll give you our expert opinion and recommendations based on our decades of experience. But, you’ll experience no sales pressure from us. Instead, we will ensure you are educated in your decision.

Why should I replace my AC?

There are many reasons homeowners might decide to replace an air conditioner. The most common reason is that they decide a new system will be more cost effective than repair. Homeowners might also replace an air conditioner if they want to increase efficiency, want a more comfortable system, want a quieter system or want a more reliable system.

What is a compressor?

A compressor is a major component of your air conditioning system, located inside the condenser. It moves the refrigerant through the system.

What is a condenser?

The outside air conditioning unit is often referred to as a condenser, which is made up of coils and a fan. This unit rejects the heat that is brought by the refrigerant from the inside of the house.

What is an evaporator coil?

An evaporator coil is part of the cooling system. It is attached to the furnace cabinet and will often look like part of the furnace. The evaporator coil is attached to the air conditioner by copper refrigerant lines. The refrigerant cools the fins of the evaporator coil, which cools the air as it passes through the coil and into your duct system.

I have a refrigerant leak, do I have to repair it?

You are not required by law to repair it. But, we always recommend finding the leak and making the repair. Your system will not be running efficiently if it is undercharged. An undercharged system could also damage your equipment and you will have the continuing cost of adding refrigerant.

Can I replace just my AC or do I need to replace my furnace as well?

Replacing only the AC portion of your system can be an option, but if the indoor coil is involved or your furnace is old, it can often be more cost effective to replace your whole system.

My air conditioner is running outside, but there is no air coming out of the vents, why?

It is possible your indoor coil is frozen, blocking airflow to your vents. A common cause of this is dirty filters. You could also have a malfunctioning blower motor or collapsed ductwork. All of which should be inspected by an HVAC professional.

Air Conditioning

What type of filters should I use?

Premium pleated filters can do a good job filtering small particles, but can reduce airflow and make your system inefficient. This is called pressure drop. Cheap fiberglass filters have less pressure drop but can let smaller particles through. We sell a middle of the road pleated filter and washable electrostatic filters, but we highly recommend Trane® Clean Effects™. Clean Effects™ has the lowest pressure drop with the highest efficiency possible.

How can I improve the air quality in my home?

Find sources of dirt and dust and eliminate them. Holes in ducts can suck dirty attic air into your house. Vacuum and dust on a regular basis to remove dust that does get into your home. Install an efficient filtration system. Monitor the humidity level in your home. A variable speed furnace will allow the fan to circulate the air constantly at a lower cost, filtering more particles from the air.

Will Trane® Clean Effects™ help with allergies?

Particles like dust, smoke and bacteria are often .3 microns or less in size. At that size, allergens can get deep into your lungs because they aren’t filtered well by your nose and throat. An effective whole-house air cleaner, such as Trane® CleanEffects™, can reduce the presence of potential asthma and allergy attack triggers in your home, like dust, pollen, pet hair and dander, dust mites, mildew, lint, fungus, most tobacco smoke, cooking grease and even bacteria.


Is it hard to apply?

Applying is simple. Contact us online to get started or call our office and we would be happy to help you through the process.

What are the current interest rates?

Give us a call to learn more about interest rates.

What if I don’t qualify through Wells Fargo?

If you do not qualify for Wells Fargo financing, it is possible we could get approval through a secondary source. Please call our office for more information.

What is the primary source of financing?

Trane® and Wells Fargo have teamed up to provide competitive financing options with approved credit.


What brands do you service?

We service all brands of residential equipment, including Trane®, Lennox, Carrier, York, Rheem, Ruud, American Standard and more.

What is your service area?

We service the entire Tulsa metro area including Bixby, Broken Arrow, Catoosa, Claremore, Coweta, Jenks, Owasso, Sand Springs, Sapulpa, and more.

How long will it take a technician to get here?

Our dispatchers will quote you a time frame when you schedule your service call. We can also call you to let you know our technician is en route, so you can meet our technician at your home or business.

Can I trust your technicians in my house?

Absolutely. All of our employees receive background checks and drug screenings.

Do you offer any service discounts?

We run a number of promotions throughout the year, and we advertise them on our website. Plus, our M Service customers receive 10 percent off all repairs, anytime.

How quickly can I get a service appointment?

Mark Hill Heating & Air has technicians dispatched all across the Tulsa metro areas, so most of the time we will be able to respond the same day.

Is there a charge if nothing is found wrong?

Only the diagnostic charge will apply. Any other charges for service will be quoted and approved by you before any work is completed.

What is your hourly rate?

Mark Hill Heating & Air does not charge by the hour. We charge a flat rate for diagnostic service, and we charge a flat rate for the repair needed. This rate will be quoted to you before any work is performed for your approval.

What is a Trane® Comfort Specialist™?

Only dealers that meet Trane®’s stringent standards and demonstrate a commitment to customer satisfaction and continuing education qualify as a Trane® Comfort Specialist™. Mark Hill Heating & Air is a charter member of this exclusive group - we have been a Trane® Comfort Specialist™ since the designation was created in 1999.

Are you a local company?

Yes, Mark Hill Heating & Air is owned locally and operates from an office in Tulsa.

Are you rated by the BBB?

Yes, Mark Hill Heating & Air is accredited and holds an A+ rating from the Better Business Bureau.

How long has Mark Hill Heating & Air been in business?

Founded in 1967, Mark Hill Heating & Air has been family owned and operated for three generations.


What is a heat pump?

When people refer to a heat pump they are usually talking about an air conditioning unit that is capable of running in reverse to heat a house. Even when the air is cold outside it still contains heat that can be extracted to heat a house.

Do you service floor furnaces?

We do not service floor furnaces. However, we can give you information about upgrading your system to a modern, more efficient one.

What is variable speed technology?

Variable speed furnaces allow for longer run times, increasing the efficiency of your system and the overall comfort in your home. Variable speed motors can also run constantly at low speed (at very low energy cost), which improves the air quality in your house.

What should I check prior to calling for service?

Sometimes the problem can be solved by something as simple as replacing the batteries in the thermostat, replacing the air filters, or even plugging in the furnace. These are some of the things you can check before calling for service.

How do I select the right furnace?

Simply call a Mark Hill Heating & Air Comfort Consultant. Our Comfort Consultants come to your home to assess your needs and help you discover the system that is perfect for your home and your budget.

How long should a furnace last?

A properly maintained furnace should last 15-20 years. Regular maintenance is the most important factor in prolonging the life of your furnace. However, many other factors can impact a furnace’s lifespan.

I have heard that ONG is giving rebates, what for?

ONG is offering rebates for improving the efficiency of your furnace and for switching from electric to gas. See www.oklahomanaturalgas.com/SaveEnergyAndMoney/EnergyEfficiencyProgram.aspx for more details.

How efficient is a standard furnace?

The least efficient furnaces sold today are 80 percent efficient. If your furnace was manufactured before 1992 it could have an efficiency rating as low as 65 percent. We sell furnaces that are up to 97 percent efficient, which are better for the environment and can save tremendously on energy costs.

Should I repair or replace my furnace?

Your furnace is a personal preference and an investment, so the final decision is yours concerning repairing or replacing it. Our job is to give you detailed, honest information about the costs and benefits of your various options. At Mark Hill Heating & Air, we take this part of our job very seriously. Whatever option you choose, we want to be your heat and air service provider for life. We’ll give your our expert opinions and recommendations based on our decades of experience, but you’ll experience no sales pressure from us. Instead, we will ensure you are confident in your decision.

My furnace comes on and goes right back off. Why?

This is called short cycling. One of the most common culprits is dirty filters. Dirty filters cause heat to build up in the system causing the furnace to shut off. Thankfully, this is an easy fix. However, faulty thermostats, dirty flame sensors, clogged vent pipes, and mis-sized equipment, can also cause short cycling. The bottom line is, short cycling can be a sign of a serious problem and we recommend you call an HVAC professional.


Do you acquire a permit for your installations?

Yes, we permit all of our installations.

What time will the installers arrive?

We will arrive between 8:30 and 9:00 on the day of installation. Special arrangements can always be made if we need to arrive at a different time. Our installers will call before leaving the office.

Why do you recover the refrigerant in my old system?

We are required by the EPA to recover and recycle refrigerant.

How many days in advance do I need to schedule?

The more notice you can provide, the better. We are often able to accommodate emergencies by replacing the equipment the same or next day. However, more notice allows us to provide the best service to all customers.

How long does an installation take?

Most system replacement installations take one full day. Duct system replacements and complicated replacements can take longer.

Can you give me a quote over the phone?

There are many different models and combinations of equipment to serve your unique needs. Therefore, we must evaluate your home, your existing equipment and your personal needs to determine your options for a new system. There is never a charge for a replacement proposal.

M Service

When should I have my system serviced?

The timing of the service is not as important as the routine. Once you establish a maintenance schedule, stick with it.

What discounts do I get as a M Service customer?

You receive a 10% discount on repairs.

How often should I have my system serviced?

We recommend having a tune-up every 6 months.

Why do you include M Service with all new installations?

Maintaining new equipment is just as important as maintaining older equipment. Also, maintenance is an important part of keeping your warranty in effect.

Are air filters included?

We do not include filters because of the multitude of sizes and types. We are happy to provide filters at additional cost, but do request pre-notification so that our technician can have them on his truck for your service. Keep in mind, your filters may be washable and reusable.

Why isn’t cleaning the blower wheel or evaporator coil included in Smart Service?

We have included maintenance tasks that most people need every year in order to keep costs down. Cleaning an evaporator coil or blower wheel can be an extensive maintenance task and should not be needed if filters are changed on a regular basis.

New Construction

Does Mark Hill Heating & Air build new homes or commercial buildings?

Mark Hill Heating & Air is not a builder. We do work with builders to plan and install the plumbing and mechanical systems for new homes. If you are a homeowner contracting your own home, we would love to talk to you and answer any questions you may have.


Are there any tax credits available?

It’s possible; however, tax credits change or expire often. We recommend that you consult your tax advisor.

What equipment is required in order to receive the promotion?

It will be stated in the offer if certain equipment is required. For example, there are some promotions that require the purchase of high efficiency equipment. This is normally classified as Trane XLi equipment.

How often do your promotions change?

Many of our promotions are seasonal, so check our website often for updated seasonal promotions and new factory promotions (which we do not know about in advance).

“I have relied on this company for several years. Everyone that I have ever dealt with has been professional and dedicated to serving the needs of the customer first. They want your business for the long haul and make honest recommendations instead of trying to sell you services and products that you don't need.”



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