How Long Do Rheem Furnaces Last?

Despite Rheem furnaces having excellent warranty coverage, being energy-efficient, and delivering outstanding performance, you might wonder if they will last long. We consulted with the experts and came up with the following information.

Rheem furnaces last approximately 15 to 20 years. The life expectancy of a Rheem furnace will depend, however, on a number of factors:

  • Sizing of the furnace
  • Installation
  • Maintenance
  • Usage

Keep reading for more details on how long a Rheem furnace lasts and signs it's time to replace it. We'll also tackle what you can do to make it last longer and the costs of replacing it.

A technician checking the furnace, How Long Do Rheem Furnaces Last?

Factors Affecting A Rheem Furnace's Lifespan 

As a homeowner, you would want your furnace to last forever. While this is impossible, in reality, most Rheem-furnaces can last between 15 and 20 years depending on several factors explained below:

Sizing of The Furnace

Sizing a furnace means matching it to the size of your home. For example, a 100 to 200 square foot room will need a furnace sized between 4000 to 8000 BTUs. A bigger house that is between 3,000 and 4,500 square feet will require a furnace of 80,000 to 115,000 BTUs.

If a small house runs on a furnace that has a higher BTU than it's supposed to be, its efficiency will decrease. Similarly, a furnace with a sizing that is too small for a big house will not work efficiently as it should.

An oversized furnace heats a room faster than it should. The thermostat turns off earlier than it should as soon as the temperatures rise high, and when the temperatures begin going down, the furnace will turn on again. 

So, if the sizing is too small or too big, the lifespan of your furnace will start decreasing.   


Poor installation of your furnace can damage it, reducing its durability. Its efficiency decreases, sometimes by 30%, which leads to higher electricity bills.

Incorrect sizing of a furnace is an example of poor installation as discussed in the previous paragraph. Also, improper connection of ducts, such as using ordinary tape instead of permanent tape, will cause the ducts to leak out warm or cool air. This reduces its capacity to condition a room and will inevitably cause the energy bills to rise.

Installing a furnace and fixing it in a humid basement, moreover, will make it prone to rust. Thus, it is important to use good workmanship and high-quality materials when assembling a furnace so that it lasts longer.


As with other electronic appliances, your furnace will require maintenance. Neglecting the maintenance routine of your furnace can lead to more frequent and expensive repairs, which is a sign its life span is declining.

Spending too much on repairs is a sure sign your furnace ought to be replaced. 


Heavy usage of your furnace will work against it, reducing its life duration because it will need frequent repairs to keep it working up to par. This is especially true for an undersized furnace as it will be pushed beyond its operating capacity. 

Hence, it’s crucial to follow the manufacturer’s instructions. If the size is not adequate, upgrade to a more powerful one, or add another appliance. 

How Can Your Rheem Furnace Last Longer?

There are no shortcuts to making your furnace last a long time. The solution is to take proper care and maintenance by doing the following:

Change The Filter Regularly

Check the manual to find out how often you need to change the filter in your furnace.

When filters get clogged with debris and dust, the airflow gets restricted, causing the furnace to work much harder, leading to faster wear and tear.

Below is a video showing how to replace a Rheem furnace filter:

Schedule Regular Maintenance

Don’t wait until your furnace has a problem. Have a technician check it at least twice a year.

A trained professional is more adept at noticing problems that you would otherwise overlook.

Also, during the check-up, your furnace can have a chance of being cleaned because the technician will definitely remove any mold and debris found, thus clearing away any blocked airways.

A furnace with blocked airways will work harder than usual, leading to a decline in its longevity.

Regulate The Humidity In Your Home

A humid room can cause the parts of your furnace to rust. A vital component like the heat exchanger, can crack and might create a potential health hazard. 

When a crack forms, carbon monoxide may leak out into the air distribution system, which can be dangerous when inhaled. 

Likewise, heat exchangers are expensive parts and can be equally costly to replace. 

Limit Usage

Turning off your furnace when not in use will make it last longer. A handy way of doing this is to upgrade your thermostat by replacing it with an automatic thermostat. 

You can install Google Home on your phone to program or control your thermostat. And so, it helps that you will use the furnace only when needed. 

Below is a video that will give you an insight on how you can use Google Home to control your thermostat to limit usage on your furnace:

When To Replace A Rheem Furnace  

Even if you have tried to extend the life of your furnace by taking good care of it, a time comes when it will have to be replaced. It may not be worth the repairs just to keep it going as it may fail at the most crucial moment when you need it most. 

Here are some of the signs that indicate the life of your furnace is coming to an end:

Aged System

As seen earlier in this post, the life expectancy of a Rheem furnace is between 15 and 20 years. So, when your furnace is nearing these years, know it is time to replace it.

Noisy Furnace

If your furnace starts producing an unusual sound, then have it checked.

Furnaces produce sounds that are non-destructive. But when you start hearing some rattling, clicking, or grinding noises, then it could be a sign it needs to be replaced.

The weird sounds may stop if a technician repairs them. If the noises persist despite the repairs, you will need to buy a new furnace.

Uneven Heating

As it ages, the furnace is unable to push out heat equally to all the rooms. When the heat is distributed unevenly in your home, with some rooms being warmer than others, it means your furnace is exhausted.

Short Heating Cycles

Normally, a furnace runs for 15 minutes in one heating cycle, before it starts to cool down. Ideally, this is 2 or 3 times in an hour. If it starts turning on and off many times more than the norm within one hour, then it is slowly dying.

Soaring Energy Bills

If you maintain your furnace well, ensuring that a technician checks it at least twice a year and following the guidelines on usage and installation, it should keep close to 95% of its original energy. This means that if a furnace is running at an efficiency of 80%, it produces 80 BTUs for every 100 BTUs gas is burned. 

However, when you notice that your bills are higher than you have been paying, then it’s a sign your furnace will stop working soon.

Inadequate Warmth

If you find you are always setting the thermostat much higher than usual to keep warm, then your furnace has begun its journey downhill.

Under normal circumstances, your furnace should provide enough warmth after setting it at the desired temperature. You don’t have to keep adjusting it upwards for it to produce the required heat.

How Much Does It Cost To Replace A Rheem Furnace?

If you were to replace a heat exchanger, the most important part of a furnace, it would cost you between $1,000 and $2,000 to replace one. The labor would generally cost $500.

Rheem furnace, on the other hand, would cost as low as $2,300 and as high as $5,890 to purchase and install a new unit. 

In Closing

A technician checking the furnace

Rheem furnaces are efficient conditioning appliances that can last long under certain factors including correct sizing of the unit, installing it properly, reducing its usage, and maintaining it well.

However, as soon as you notice signs that it is declining in its capacity to operate, you would rather replace it than call a technician to do the job. This is because the repairs will start being expensive.

Have a look at our previous posts and find out how to troubleshoot when a Rheem water heater starts leaking and how a smart thermostat can improve the efficiency of your furnace:

Rheem Water Heater Leaking—What To Do?

How Big Is Nest Thermostat?

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