Rheem Tankless Water Heater Review

Last Updated on: 15th September 2023, 07:29 pm

Some of you are still stuck in the Stone Age with those clunky old water heaters. Don’t you all know that tankless is the way to go?

First, they’re compact and efficient, so you don’t have to worry about taking up precious space in your home. And the best part? You only heat the water you need, so you’re not wasting any energy or money on heating the water you won’t use. Isn’t that neat as a pin?

But let’s get down to the nitty-gritty. Rheem tankless water heaters are as reliable as all get-out. They’re built to last; their customer service is second to none if you ever have trouble. And trust me, I’ve dealt with my fair share of plumbing problems in my day.

Table of Contents

How Does A Rheem Tankless Water Heater Work?

These water heaters heat the water as it flows through the unit. Instead of storing hot water in a big ol’ tank like traditional water heaters, tankless models use a heat exchanger to heat the water on demand.

When you turn on the hot water tap, the flow sensor in the unit detects the water flow and sends a signal to the computer board. The computer board then activates the burner or heating element, which heats the water as it passes through the heat exchanger.

And here’s the beauty of it – the unit only heats the amount of water you need. So, if you’re washing your hands or filling up a small pot, the unit won’t waste energy heating a whole water tank. It’s like having your hot water genie – it’s there when you need it and gone when you don’t.

Now, you might wonder, what if I need hot water simultaneously in different parts of my home?” Well, fear not, my friend. Rheem tankless water heaters come in different sizes and can be installed in series or parallel to meet your hot water needs. Isn’t technology grand?

Adjusting Temperature

Adjusting the temperature on a Rheem tankless water heater is a breeze.

First, you’ll need to locate the temperature control panel on your unit. This might be located on the front of the unit, or it might be a remote control that’s mounted on the wall. Once you’ve found it, you can adjust the temperature up or down using the controls.

Now, it’s important to note that the maximum temperature setting on most models is 140 degrees Fahrenheit. This is for safety reasons, as higher temperatures can scald the skin. But you can adjust the temperature to a comfortable level for your needs.

One thing to remember is that adjusting the temperature can affect the hot water flow rate. If you set the temperature too high, the unit might be unable to keep up with the demand, and you’ll experience lower hot water flow. Conversely, if you set the temperature too low, you might get a higher flow rate, but the water might need to be hotter.

So, the key is to find the sweet spot that’s just right for you. Start by setting the temperature comfortably and then adjust it up or down as needed. And if you need help with how to adjust the temperature or if you’re experiencing any troubleshooting issues, feel free to call a professional plumber for help.

Types Of Rheem Tankless Water Heaters

These come in three main types – electric, natural gas, and propane. Let me give you a quick rundown of each type.


Electric tankless water heaters are powered by electricity and are typically smaller than gas models. They’re a good option for homes that don’t have access to natural gas or propane. Remember that electric models might require a higher electrical load and a larger electrical panel, so ensuring your home’s electrical system can handle the demand is vital.

Natural Gas

Next up, we have natural gas tankless water heaters. These units are powered by natural gas and are known for their high flow rates and efficiency. They’re an excellent option for homes with a natural gas supply, and they can provide a constant hot water supply for multiple appliances simultaneously.


And last but not least, we have propane tankless water heaters. These units are powered by propane gas and are a good option for homes that don’t have access to natural gas but have a propane supply. They’re also a good option for homes that have high hot water demand and need a unit with a high flow rate.

It’s important to note that each type comes in different sizes and models to fit your hot water needs. Regardless of your type, all models are known for their reliability and efficiency. So, take your pick and enjoy hot water on demand.

Some Of The Different Models Available

Awesome Features

These are essential details to consider when choosing a Rheem tankless water heater for your home. Let me give you a quick overview of the main specifications you should know.

  1. Flow Rate is the amount of hot water the unit can produce simultaneously, measured in gallons per minute (GPM). The flow rate will depend on the size of the unit and the type of fuel it uses. For example, a natural gas unit might have a higher flow rate than an electric unit.
  2. Energy Efficiency – This is measured by the unit’s Energy Factor (EF), which tells you how efficiently the unit uses energy to heat up water. A higher EF means the unit is more energy-efficient and will save you more money on your utility bills.
  3. Temperature Range – This is the temperature range that the unit can produce, measured in degrees Fahrenheit. As I mentioned, most have a maximum temperature of 140 degrees Fahrenheit for safety reasons.
  4. Size – This refers to the unit’s physical size, which can vary depending on the model and fuel type. Electric units are typically smaller in size compared to gas models. It’s essential to ensure the unit you choose can fit in the space you have available in your home.
  5. Venting Requirements – This is important for gas and propane models, as they require proper venting to prevent carbon monoxide buildup. The venting requirements will depend on the unit’s size and location.

These are the main specifications when choosing one for your home. Research and select a unit that fits your hot water needs and budget.

Warranty Info

Warranty is essential when choosing a Rheem tankless water heater for your home. Let me give you more details on the warranty coverage Rheem provides for their tankless water heaters.

Rheem offers a limited warranty on their tankless water heaters that covers the unit for manufacturing defects or failures for a specified time. The exact length of the warranty will depend on the model and fuel type of the unit.

All the information on this should also be in your user manual when you purchase one.

How Much Does It Cost?

I recommend looking at this page and seeing each model and its prices.


The pros of Rheem tankless water heaters – where do I begin? Using one in your home has plenty of benefits. Here are just a few:

  1. Energy Efficient – They are highly energy efficient, as they only heat the water you need on demand. This means you’re not wasting energy heating a whole tank of water when you don’t need it, which can save you money on your utility bills.
  2. Endless Hot Water – You’ll never run out of hot water again! The unit heats the water on demand, so you can use hot water for as long as you need without worrying about running out.
  3. Compact Size – They are smaller than traditional tank water heaters, so they occupy less space in your home. This can be a significant advantage if you have limited space for a water heater.
  4. Longer Lifespan – They typically have a longer lifespan than traditional tank water heaters. With proper maintenance, they can last up to 20 years or more, significantly longer than a tank water heater.
  5. Environmentally Friendly – They are better for the environment, as they use less energy and produce fewer greenhouse gas emissions than traditional tank water heaters.

So, there you have it, folks! These are just a few benefits of using one in your home. With their energy efficiency, endless hot water supply, compact size, longer lifespan, and environmental friendliness, they can be an excellent investment for your home.


While Rheem tankless water heaters have many benefits, like any other product, they also have some potential drawbacks or cons that you should consider before purchasing. Here are a few:

  1. Maintenance Requirements – require regular maintenance to ensure they operate efficiently and last longer. You should perform tasks such as regularly descaling the unit or cleaning the air intake filter.
  2. Flow Rate Limitations – While they can provide endless hot water, they are limited by their flow rate. If you have multiple appliances using hot water simultaneously, such as a shower and a dishwasher, the unit might need help to keep up with the demand.

These are potential drawbacks or cons of using one in your home. Make sure to weigh these against the benefits before making a decision.

Are Rheem Tankless Water Heaters Good?Conclusion

Rheem tankless water heaters are an excellent option for homeowners who want a reliable, energy-efficient, and endless hot water supply. Their compact size, longer lifespan, and environmental friendliness make them a wise investment for your home.

However, it’s essential to consider both the pros and cons before purchasing. While they offer many benefits, such as energy efficiency and endless hot water, they also have potential drawbacks, such as higher upfront costs, installation complexity, maintenance requirements, flow rate limitations, and dependency on electricity or gas.

If you purchase one, choose the suitable model and size for your home, follow proper installation and maintenance procedures, and keep the warranty information safe if you need to make a claim.

Overall, Rheem tankless water heaters are a reliable and efficient option for homeowners who want a consistent and endless hot water supply.