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Rheem FAQ

Rheem FAQ


Frequently Asked Questions

Get answers to all the most frequently asked questions (FAQs) about Heating, Cooling & Water Heating.

Heating & Cooling FAQs

Who do I contact for air conditioning products and service?

For questions concerning new products, energy efficiency ratings, savings on your utility bills, or repair or replacement services, call your local Rheem dealer. He can answer all of your heating and cooling questions.

What do rating numbers mean?

The U.S. government requires an efficiency rating of all air conditioning and heating equipment. The rating reflects the percentage of energy used efficiently, with a high rating indicating high-efficiency. The next two topics address this issue in greater detail.

What is a SEER?

There are special names for the efficiency ratings of various types of equipment. Air conditioning equipment is rated by the Seasonal Energy Efficiency Rating, or SEER. The higher the SEER rating, the more efficient the unit.

What does HSPF stand for?

There are special names for the efficiency ratings of varying types of equipment. Heat pump equipment in the heating mode is rated by the Heating Seasonal Performance Factor, or HSPF. The higher the HSPF rating, the more efficient the unit.

What does AFUE stand for?

There are special names for the efficiency ratings of various types of equipment. Gas furnaces are rated according to their Annual Fuel Utilization Efficiency, or AFUE. The higher the AFUE rating, the more efficient the unit.

Should outdoor units be covered in winter?

Rheem heat pumps operate year-round and should never be covered. Similarly, air conditioners that operate seasonally are built to withstand an outdoor environment and should not be covered.

Should a thermostat’s fan setting be on "auto" or "on"?

Preferably auto. That way, the fan operates only when the temperature requires it. This is the most used and the most efficient setting. However, there are advantages to using the “on” setting. Air is constantly filtered through the unit’s air filter, and the constantly circulating air results in an even temperature throughout the house.

Can shrubs or flowers be planted around an outdoor unit?

However, we recommend that plants be no closer than 18 inches from the unit. This allows for plenty of room for air circulation in and out of the unit. Without this room for air circulation, the unit could overheat, resulting in a premature need for service.

If an outdoor unit needs replacing, should the indoor unit be replaced too?

Rheem air conditioning and heating units are designed to operate as a complete, matched system. The efficiency rating is based on the entire system. Replacing the entire system ensures the system will be reliable and efficient.

How do I know what size unit our house needs?

Your Rheem dealer, who will consider many factors before making a recommendation: size of the house, climate, number and type of windows installed, insulation, and even the number of people living in the house.

What is the difference between a split system and a package unit?

A split system uses indoor and outdoor components to provide a complete home comfort system. A package unit or self-contained unit requires no external coils, air handlers, or heating units.

How do I find a Rheem dealer?

Use the Dealer Locator page on this Web site or refer to your telephone directory. Rheem dealers are located nationwide.

How do I find my Model and Serial Number?


The label containing model and serial number information can be found on the front of a tank-type water heater.



The label containing model and serial number information can be found on the front or on the right hand side of a tankless water heater depending on the model.

Why do I need a load calculation for my home for heating and cooling products?

It is important that the type of equipment in your home is properly matched to its square footage as well as other relevant factors. A load calculation from a certified, independent Rheem Pro will evaluate various aspects of your home for an energy efficient match such as:

  • Climate that you live in
  • Size, shape and orientation of your home
  • Square footage
  • Type and how much insulation you have
  • Quantity of windows, their size, type and the direction they face
  • Measurement of walls
  • Vents and ductwork
  • Seals and estimate air leakage
  • Type of materials your house is made of

All of these factors will help your dealer find a system that will work for your home and provide energy efficient savings.

Where can I purchase filters for my Heating & Cooling equipment?

You can visit the Rheem Store where you will find an assortment of high efficiency, high quality, and durable replacement parts for your Rheem Products.

How do I register my equipment?

If you have purchased a Rheem heating, cooling or water heating product you can quickly register your unit online at Rheem Product Warranty Information

The Warranty Information page can also assist with verifying your warranty registration in case you are feeling unsure or just want to double check that the registration has been input.

How do I contact a Rheem dealer?

Rheem offers a quick and easy process for locating a dealer near you. Our Find a Pro allows people to search by ZIP code and category; such as Heating and Cooling and Tankless Water Heaters.

Does Rheem have a consumer financing program?

Rheem offers a quick and fast way to apply for the Rheem® KwikComfort® Financing program. Kwik Comfort representatives are available seven days a week to assist you at any time with questions you may have. You are offered and assisted with:

  • Easy application process
  • Quick and efficient credit processing
  • Instant credit for future purchases
  • Low monthly payments

There are a variety of financing options for you. Don’t hesitate to ask your Rheem Dealer for more details.

What can I find in the Homeowner Center?

The Homeowner Center has a variety of recourse brought together in one area so that the customer can take care of their tasks quickly and can also seek assistance. At the Homeowner Center you can:

  • Register or verify your warranty
  • Find rebates for your Rheem products
  • Find local contractors
  • Find products
  • Receive support on products you want to know more about

Water Heating FAQs

What is FVIR?

FVIR stands for Flammable Vapor Ignition Resistant. An ANSI (American National Standards Institute) standard went into effect in July 2003 that will prevent a water heater from igniting flammable vapors outside the combustion chamber. This helps to protect homes.

Are all FVIR water heaters the same?

No, they are not. The consortium of manufactures agreed on flame arrestor plate technology to create the new generation of FVIR water heaters. Early in the development, Rheem researchers at their Montgomery labs discovered that flame arrestor plate designs might be vulnerable to the effects of lint, dust and oil (LDO). Rheem urged the ANSI standards be reviewed. As a result, the ANSI standard now includes testing for reliability in LDO environments. Throughout development, Rheem engineers have been highly attentive to the role LDO robustness will play on product reliability and consumer satisfaction.

What is the Rheem® Hybrid Electric Heat Pump Water Heater all about?

The Rheem Hybrid has a 10-year tank leak warranty and a 10-year parts warranty. It also has a first-year in-home labor warranty. This water heater uses heat pump technology to achieve a 3.55 uniform energy factor. (Residential gas is approximately 0.62; and residential electric is approximately 0.92). The Rheem Hybrid is also EnergyStar Compliant and may qualify you for a local or utility rebate.

How can I determine which water heater is right for me?

Choosing a water heater is based on your family size and how much hot water you will use in one continuous hour. We call it Peak Hour Demand.

What is the longest warranty Rheem offers?

The Rheem Marathon® water heater offers a LIFETIME warranty. The Marathon is a special water heater that has a seamless blow molded polybutene inner tank. It will not rust. The several inches of foam insulation give it up to 0.93 uniform energy factor. Tank sizes range from 15 gallons to 105 gallons to fit any household need. Once you purchase this water heater, the lifetime warranty is extended to the original owner when installed in a residential application.

I need to vent my gas water heater several feet away from an outside wall. Which product is best for me?

There are a couple of products that may work in your application. The Power Direct Vent is a seal combustion, direct vent water heater that may be installed up to 60 feet away from the homes outside wall. We also have a standing pilot Direct Vent that will vent up to 4 feet from the outside wall.

Do you make water heaters designed for commercial applications?

Yes, we do. We have a full line of standing pilot, intermittent spark, direct vent, sealed combustion and high efficiency commercial water heaters. Our Xtreme models will provide up to 756 gallons of hot water in an hour; and recover the tank contents in as little as 8 minutes! You can select from an electric model or gas model.

How can I find a local installer of Rheem Water Heaters?

Visit our Find a Pro page an enter your ZIP code to be presented with a list of trustworthy, independent Rheem installers in your area.

Is there an upgrade to your normal tank leak warranty?

Yes, there is. During the installation of your new water heater, you can add this kit and receive an additional four-year tank leak warranty. This kit will fit most Rheem residential gas and electric water heaters.

What is NAECA?

In order to effectively reduce home appliance energy use, conserve more natural resources and generate significant energy cost savings for homeowners, the U.S. Department of Energy (DOE), as part of the National Appliance Energy Conservation Act (NAECA), periodically requires higher energy efficiencies on almost all residential gas, electric, oil and tankless gas water heaters. In 2015, new efficiency standards were enacted that required many manufacturers to increase the size of their water heaters. Several Rheem water heaters already fit within the new NAECA standards, and others were made compliant without significantly increasing their size. The result is that many Rheem water heaters are up to 2″ smaller than competitive models.

Tank vs Tankless Water Heaters

Rheem Tankless Features

  • Continuous hot water
  • High energy efficiency
  • Compact, space saving design
  • Electronically controlled
  • Exclusive sensing burner technology
  • Exclusive film wrap overheat protection
  • Digital thermostat with self diagnostic program
  • Precise temperature control
  • Consistent hot water supply temperature
  • No hot water storage
  • Low Operating Costs
  • Low NOx emissions – all models
  • Indoor or outdoor models available
  • Two High altitude options: up
    to 6,560 or 9,840 ft. elevations
  • Click here to browse our high efficiency tankless water heaters!

Rheem Tank Features

  • Low first cost
  • Low venting cost
  • No electricity required
  • Large variety of sizes available
  • Flow rates of 12gpm and up
  • High altitude installations to 10,000 ft
  • Low NOx emissions – some models
  • Click here to browse our residential tanks!

Tankless FAQs

What is a tankless water heater?

Tankless water heaters are compact in size and provide a steady flow of hot water for as long as you need it. Rheem tankless gas water heaters are more energy efficient than conventional water heaters, because the tankless models eliminate the need for reheating stored water.

How does the Rheem tankless water heater work?

A conventional tank-style water heater stores hot water, and heats the water 24/7, whether you use it or not. The new generation Tankless Technology Water Heater from Rheem only heats water on demand. When the faucet is opened, the water flows through the Rheem Tankless Water Heater, which heats it to the temperature you’ve digitally set. When the faucet is closed, the Rheem Tankless Water Heater senses the command, and goes to standby mode.

Can it be installed in the same place my old water heater was installed?

As long as enough combustion air is provided, Rheem tankless water heaters can be installed in a utility room, garage, basement or attic, or on an outside wall . Plus, they can be installed in locations where a storage water heater may not fit. The Digital Temperature Controller can be mounted in any room.

What is the Uniform Energy Factor (UEF) for the Rheem Tankless Water Heaters?

In 2017, the Department of Energy required manufacturers to calculate the UEF based on how efficiently each water heater uses energy in real-world usage scenarios. The standard was intended to enable homeowners to compare the efficiency one water heater to another. UEF replaces the old standard, Energy Factor (EF), which didn’t allow easy comparison.

Does this mean tankless water heaters have lower operating costs?

A higher EF is only one of many reasons why tankless water heaters cost less to operate. A Rheem tankless water heater has no standing pilot light, no stand by loss, and the burners modulate to maintain maximum efficiency.

Does Rheem offer customer service for their tankless water heaters?

Yes! Rheem Tankless Water Heater Customer Service is available 7 days a week/7 a.m. to 7 p.m. Central Time. The professional staff provides fast, reliable service. Customer service options are available, please call 1-866-720-2076 (this number is only for tankless water heater customer support; for HVAC-based customer support, please reach out to your local independent Rheem Pro with all service-related questions.

Can you adjust the water heater setpoint temperature setting in 1 degree increments?

No, the minimum temperature adjustment for RTG series waters heaters is a 2 degree increments from 100 F up to 120 F and 5 F increments from 120 F to 140 F.

What safety device is used to prevent overheat failure of the heat exchanger?

An Over Heat Limiting Film wrap is wrapped around the entire heat exchanger. This monitors the temperature of the heat exchanger and will shut the unit down if it exceeds a safe temperature. This is an exclusive feature of the Rheem tankless water heaters.

What is the minimum clearance on the back, sides, top, bottom, and front of the water heaters?

0″ back, 1/2″ sides, 12″ top, 12″ bottom, and 12″ front.

What does the sensing burner do?

The sensing burner is a device that detects incomplete combustion during operation of the water heater. If incomplete combustion is detected, the water heater corrects the problem to provide clean, efficient water heater operation at all times. This is an exclusive feature of the Rheem tankless water heaters.

Is there a standing pilot?

No, the direct ignition sends a spark to the main burner when hot water flow is detected. This feature improves the energy efficiency of the water heater.

Can I convert the water heater from LP to natural gas or natural gas to LP?

No, these units cannot be converted from one fuel source to another.

Where in my home can I install a Rheem tankless water heater?

The RTG-64DV, RTG-84DV, and RTG95DV may be installed in all locations, including bedrooms and bathrooms. These units obtain combustion air from the outdoors. These models are not designed for use in mobile homes. The RTG-64X, RTG-84X, and RTG-95X outdoor models are for outdoor installations only, and are a great alternative if your climate is appropriate. This saves space and the cost of venting.

What are some reasons to use a tankless water heater over a standard storage-type water heater?

Tankless water heaters can provide a continuous supply of hot water, while a tank will run out of hot water. Tankless products also have a longer life; lower operating costs, precise delivery temperature, and can be installed in many locations where a storage water heater may not fit.

How much can I expect to save on my monthly bill if I install a tankless water heater?

Test results have shown that a tankless gas water heater costs about 40% less to operate than an electric water heater, and about 30% less than a natural gas water heater.

How much more do they cost to purchase?

Generally, a tankless water heater will cost about 2 to 2-1/2 times as much as a standard water heater to purchase and install. Keep in mind that in addition to lower operating costs, useable square footage is gained by choosing tankless!

Buying Online FAQs

I found a good deal online. Should I purchase from an online sales site?

ONLINE BUYER BEWARE!!  Heating & Cooling products are unlike most products for sale on the Internet. A trained professional should always review the unique requirements of your structure to ensure proper equipment selection and safe, efficient installation. Even the most skilled  Do-It-Yourselfers should not attempt to install Heating & Cooling products. Consumers should never install heating and cooling products themselves. A professional Heating & Cooling Contractor should always be involved in job-site inspection, product selection, and installation. WARNING!!  There are many online sales companies that engage in the dangerous and deceptive practice of selling Heating & Cooling equipment directly to Consumers bypassing the expertise of trained, professional Contractors. These unscrupulous companies advertise “Savings By Cutting Out the Middle Man by Buying Direct”.  There is no short cut to a safe, quality, professional Heating & Cooling installation that conforms to local building codes, meets manufacturer specifications, performs at peak efficiency, and operates safely. Prior to purchasing Heating & Cooling equipment, a local professional Heating & Cooling Contractor should visit your home in person, evaluate your structure, assess your current Heating & Cooling system, review your family’s air quality requirements, and submit a written proposal that specifies his professional recommendation of appropriate equipment options before you decide on what type of system you should buy.

Why is a Contractor visit important?

A Heating & Cooling system that’s too small won’t keep your home comfortable and one that is oversized will not maintain acceptable humidity levels or be efficient. Oversized systems cycle (turn on and off) more than necessary; this cycling wastes precious, expensive energy; puts undue strain on components like compressors; and often reduces the expected life of the system. A professional Contractor will determine the optimal size of Heating & Cooling equipment for your home by making a careful study of your cooling requirements by performing a heating and cooling Load Calculation of your structure. A Load Calculation is a scientific process that uses industry-standards that take into account the number of windows and doors in your home, window dimensions, and average number of hours of sun exposure. Subtleties like shade trees and shrubbery in your yard, open floor space, the R-value of wall, floor, and roof insulation, local climate patterns, the design and condition of your current central duct system, number of heat-generating appliances, the type of interior furnishings, number of fireplaces, and many other factors effect in unique ways the heating and cooling requirements of every Heating & Cooling system. Only an in-person home visit by a trained Heating & Cooling professional contractor can ensure that you buy the right equipment that your home requires to be safe and efficient for a long time.

Does Rheem approve any online resellers of Heating & Cooling equipment?

Rheem does not endorse, approve, or certify any online sale of its products through auction websites, online retailers or any other method of online sales direct to consumers without an in-person site visit, inspection, and installation by a qualified, trained Heating & Cooling professional).

What happens if I purchase Rheem equipment from an online sales company?

Rheem published warranties are not applicable for any equipment manufactured by Rheem that has been sold direct to the consumer via the internet or auction websites without an in-person site visit, inspection, and installation by a qualified, trained Heating & Cooling professional.

How do I contact a Contractor to make an equipment purchase?

Please use the Find a Pro system on the left side of this website to locate a professional Contractor near you. Please note that the Contractors listed on the Find a Pro system are independent contractors and are not owned by, employed by, operated by or authorized by the Rheem Sales Company.

What should I look for in a professional Heating & Cooling Contractor?

Consider the following:

  • Reputation – Ask for a list of customers and check references. A call to the Better Business Bureau is worthwhile. Contractors who are members of the Air Conditioning Contractors of America, the Plumbing-Heating-Cooling Contractors Association, and other similar professional contractor groups most likely have a commitment to professional standards and ethical business practices. Check with the Rheem Wholesale Distributor in your area for names of dependable, reputable contractors.
  • Credentials –Ask about required certifications. Many states, provinces, cities, and towns require Heating & Cooling contractors to be licensed; check local requirements and be sure your contractor meets the required standards. Ask about recent training received; new and long-tenured contracting businesses regularly invest in professional Heating & Cooling technical training to stay current. North American Technician Excellence (NATE) certification is the Heating & Cooling industry’s leading authority for technical certification of Heating & Cooling technicians; the industry’s best contractors have some level of NATE certification and proudly display their credentials on their websites and in their advertising. To learn more about NATE certification, please visit or call 1-877-420-NATE.
  • Commitment – Look for a dealer you see as active, present and involved in your local community. You want a local contractor who is close by, who cares about your needs, who has a commitment to your community, and is able to provide fast, dependable, convenient service when you and your family need it. Look for a contractor who will be there in your hometown tomorrow to help you maintain and service what you purchase today.


How do I register Heating & Cooling equipment that I install?

Visit the warranty registration page for warranty verification and product registration.

How do I get added to the Find a Pro page?

To get your company on our locator and start receiving leads, visit the Join the Rheem Team page and filling out a short form.


What is the Rheem builder program?

Rheem offers a rebate program for home builders which include all the residential products including IAQ products, offer from the divisions. Products from Raypak are not part of this program.

Where can I purchase the full line of Rheem products?

Builders currently purchase equipment through our Rheem or Ruud pros who are purchasing through our distributors.

Architects / Engineers

How do I get a copy of your product catalog?

Please visit the contact form and enter your information. Be sure to request a catalog in the comments field.

How do I size Rheem products?

Rheem has developed several tools to help you size and pick the products that are right for you.


What energy efficient products are available for CO-OP programs?

Electric cooperatives can purchase Rheem Marathon, solar and hybrid products.

How do I order bill stuffers?

Co-operative customers order bill stuffers direct from WHI.


How can I become a Rheem Distributor?

To become a Rheem Distributor please visit our contact form (link to contact page) and indicate your interest in becoming a distributor in the comments field. A Rheem representative will contact you.

How can I add a contractor to the Dealer Locator?

You can add a contractor through our contractor information management system (CIMS) in our Rheem Partners portal. If you need access to the Rheem Partners portal, please visit

How do I register my equipment?

Please visit the Warranty Registration page.