Rheem Air Conditioner Reviews

The Truth About Rheem Classic 90 Plus Series: A Closer Look

As professionals and consumers alike become more aware of their energy usage, demand for more energy-efficient appliances continues to grow. Highlighting efficiency ratings and other performance metrics has become commonplace in the home appliance space, so buyers know exactly what they’re getting. While some manufacturers have caught on to this trend sooner than others, most models are now equipped with similar technology that meets desired performance standards. 

When it comes to identifying which products use the least amount of energy, there is one brand that stands out from the rest: Rheem. Whether you’re shopping for a water heater or an entire home heating system, Rheem’s unique branding strategy makes it easy to identify the most efficient in line that is available on the market today. But how does Rheem stack up against its competitors? Let’s take a closer look at the information or details you need about the Rheem Classic 90 Plus Series.


The Rheem Classic 90 Plus high-efficiency gas furnaces provide efficient and pleasant household heating systems. Rheem classic 90 plus high-efficiency gas furnaces are produced for simple installation and sanctioned by CSA. Rheem classic 90+ furnaces are a favorite among homeowners who experience long and cold winter seasons. Rheem 90-Plus gas furnaces are suitable for utility rooms, closets, alcoves, or crawl spaces.

This furnace is economical and suitable for heating your home, eliminating high utility bills, and providing the best domestic heating solution for your family. Using dual aluminized steel heat exchangers, this furnace achieves an efficiency (AFUE) of 90+. All their product is quick and simple to install and have a 34-inch height for upflow, horizontal, and downflow setups.

Rheem Classic 90 Plus Features

A furnace operating at 70% of its capacity is generally enough to satisfy most heating demands until a need for greater heat is identified. The Rheem Classic 90 Plus model allows the system to operate at a lower level for improved efficiency.

Here is some info about the Rheem Classic 90 Plus:

  • Stainless steel is utilized throughout the heat exchanger for corrosion resistance and thermal fatigue reliability. 
  • The low-profile 34-inch design is lighter and easier to handle and allows for optional accessories. 
  • On upflow models, gas, electricity, and condensate drain connections are situated on the left or right side. 
  • The integrated control board manages all operational functions, as well as hookups for humidifiers and electronic air cleaners. 
  • This furnace is one of the quietest on the market due to its insulated blower compartment, slowly opening gas valve, and specially designed inducer. 
  • A cabinet that is pre-painted galvanized steel is used.
  • All flow models are equipped with either an indoor or outdoor combustion air pipe. 
  • A special fitting is provided to ease installation. 
  • Diagnostic control boards and fuses protect the transformer and controls. 
  • A solid base is standard.
  • With Rheem Classic 90 Plus, the furnace operates at a lower stage, thus improving efficiency.

Rheem Classic 90 Plus Price

Although the Rheem Classic 90 Plus gas furnace costs a bit more, you’ll get everything you want for it. You’ll have lower energy bills and a comfortable home heating system as a result. The price is for the unit only and is $1,150 for the 45,000 BTU for the RGRA-04MEAS model and $2,100 for the 120,000 BTU version.

Rheem Classic 90 Plus Troubleshooting

The Rheem 90+ efficiency condensing units are some of the most reliable and efficient gas-fired condensing units on the market. However, that doesn’t mean they’re perfect. Even top-notch products will have issues from time to time. The key is catching problems before they become a big problem. Here are a few things to look for when troubleshooting your Rheem Classic 90+ gas condensing unit so you can get it up and running again as quickly as possible.

Rheem Classic 90 Plus Common Problems

There are a few common problems that owners of Rheem Classic 90 Plus furnaces have reported. These include issues with the furnace not igniting, the furnace shutting off prematurely, and the furnace cycle not completing. In some cases, these problems can be resolved by resetting the furnace, but in other cases, they may require expert repair.

This list includes:

  • Your Rheem furnace does not produce heat. 
  • Your heating system sounds like it’s working but doesn’t produce heat. 
  • Your furnace isn’t starting. 
  • Your heater runs continuously even when you set it to the lowest setting. It won’t shut down or turn off once it reaches the desired temperature. 
  • The furnace is working harder than it should. You can feel the unit’s housing getting warmer as you touch it. 
  • Your unit heats some rooms but fails to heat others. 
  • Your utility bill is higher than the average winter usage. 
  • You may notice a strong gas odor coming from your furnace, particularly as it warms up.

How to Troubleshoot Rheem 90 Plus?

The Rheem C90 Plus troubleshooting should be performed with the unit turned off. Remove the plug from the outlet, take off the control door, and shut off the gas control pressure switch before starting. After you’ve switched off the gas control switch, leave the house for 5 minutes to allow the gas in the supply lines to dissipate. You should not smell the gas. If you do, turn off the gas control switch and call the fire department immediately. Here are some tips you should try if you encounter a problem with your furnace:

Power Issues

There are a variety of issues that may arise with the operation of your heater. Prior to addressing any other concerns, you should verify that your heater is powered on, plugged into a power outlet, and working properly. If your heater is not receiving power, you should reset the circuit breaker if it has tripped off. If your circuit breaker is off, you should check for damaged wires that have turned black. A burnt-out fuse should also be replaced.


See if the thermostat’s setpoint is set at a higher temperature than normal. If it is, press the reset button twice. Also, check the thermostat’s batteries and replace them if necessary.


You should deactivate your furnace if it does not produce heat or an odorous gas when turned on. Immediately unplug the furnace from the power source and remove the control panel. Then, turn off the gas control switch and wait a moment. Remove the filter from the furnace’s front panel after shutting off the gas control switch. After cleaning the filters with a few drops of dishwashing liquid and water, rinse and air-dry them thoroughly before putting them in the Rheem furnace. Turn the switch back on and close the control panel. Finally, turn on the furnace’s power position.


If the igniter on the furnace isn’t working, you’ll need to relight the pilot. Make sure to dry up any water around the pilot light if it fails to light, as well as any water. You can examine the transformer with an insulated screwdriver to see if it’s working properly. When you touch one of the terminals with the screwdriver, you should also check the power arcs. If the current is low, you must replace the transformer. Any broken or corroded wires, as well as electrodes, must be changed. You must also check the pilot thermocouple and replace it if necessary.

Combustion Chamber

Your Rheem C90 heating system may be overheating if you can feel the heat coming from the combustion chamber door. A buildup might heat proper ventilation if you notice the heat at the door. You should clean the exhaust pipe, chimney, and combustion chamber as well. If the heat exchanger and seals are broken, they should be replaced.


Certain rooms may be heated by the unit, so check the vents in your rooms for dirt. Broken exterior piping should be replaced. You should also clear obstructions from interior vents if any exist.

Classic 90 Plus Reviews

A lot of reviewers on HVAC-talk.com think the Classic 90 Plus is a high-quality, affordable option for economical heat pumps. It appears that several customers feel otherwise, based on the posts on do-it-yourself.com and justanswer.com. 

Although there are exceptions, consumers frequently complain about the following symptoms: insufficient or improperly installed equipment, system not lighting up, hard-to-read diagnostic messages, defective components, and sudden stoppages and starts. Installation problems and size are also common. Rheem has a history of problems, but the solution is the proper installation by a professional industry professional. You will have twenty years of comfort if an experienced HVAC contractor installs and maintains it properly.

Classic 90 Plus Warranty

Most Rheem furnace models on the Classic 90 Plus series are covered by a limited lifetime warranty. Every other component has a 5-year parts warranty. You must register your Rheem gas furnace after installation to receive the full warranty benefits.


One of a variety of heating, air conditioners, and water heater solutions from Rheem, the Classic 90 plus series has everything you need to make sure that your home is a temperature-controlled year around. Featuring the finest in energy efficiency, along with a wide range of customized options, this is an excellent choice for any do-it-yourself homeowner looking to take on some serious heating or cooling challenges.


How long does a Rheem 90-plus furnace last?

Rheem 90-plus furnaces have an average lifespan of 15 to 20 years. However, proper maintenance is key to prolonging the life of your furnace. Routine maintenance tasks such as changing the air filters and having furnace services annually can help to keep your furnace running efficiently and prevent premature wear and tear.

How many BTU is a Rheem Classic 90 Plus furnace?

The Rheem Classic 90 Plus furnace has a BTU of 45,000. This furnace is designed for use in homes with a central heating and cooling system. The furnace has an AFUE rating of 95%, which means that it is efficient in converting fuel to heat.

Is a 90 percent furnace worth it?

An electronically commutated blower motor, also known as an ECM, is used on many of these furnaces to provide even more heating and save energy. An ECM runs continuously at variable speeds, saving energy and providing even more heating. 90% of furnaces are more efficient at burning fuel, but there are many more options for saving energy and boosting home comfort.