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Everything You Want to Know About Tankless Water Heaters

May 19, 2022
tankless water heater

You may have heard about tankless water heaters, but how much do you know about them? We wanted to gather some of the top questions people have about tankless and put it all in one place. This will save you some time researching and help you decide if a tankless water heater is right for you. We’ll take some of the mystery out of a tankless and you’ll be well-informed on the benefits of a Rheem® tankless. This article focuses on gas tankless water heaters.

Why do people purchase a tankless water heater?

Switching to a tankless water heater has its benefits including space and energy savings, lower utility bills and continuous hot water. A great benefit is not having to worry about running out of hot water when you have a busy day filled with dishes, laundry and showers. No more waiting for a hot shower or running out of hot water in the middle of a shower.

tankless water heaterDoes a tankless water heater really provide endless hot water?

Rheem tankless water heaters have flow rates of up to 11 gallons per minute. That’s enough for three showers, AND washing dishes, AND filling the washing machine – all without running out of hot water. Your ground water temperature affects your flow rate, so check with your plumber on the best model for you.

How does a tankless water heater work?

When a hot water faucet is opened, cold water starts flowing into the unit where a flow sensor inside the water control valve activates the gas burner. The gas burner ignites and begins to heat the water continuously as it passes through the heat exchanger where it is heated to the set temperature and then through to the open faucet. Once the faucet is closed, the flow sensor in the water heater stops detecting the water and the unit will shut down immediately.

How does a Rheem tankless water heater reduce cold water bursts?

While a typical tankless unit will shut down immediately when the hot water faucet is turned off, Rheem tankless water heaters feature Hot Start Programming™. It keeps the unit in a ready state for five minutes after the initial need for hot water has ended. This means the unit will begin heating the water immediately if there is back-to-back hot water usage helping to minimize cold water bursts.

What is the difference between a condensing and a non-condensing tankless?

Non-condensing tankless water heaters have one heat exchanger that produces exhaust gases at a much higher temperature as they leave the unit. Condensing tankless water heaters are much more efficient than non-condensing water heaters because they have two heat exchangers. Water passes through a secondary heat exchanger first which preheats the water before it flows through the primary heat exchanger. This process pulls heat from the exhaust causing a vapor to form which then cools the exhaust to a much lower temperature allowing for lower cost materials such as PVC to be used for venting.

How much space does a tankless water heater save you?

A standard tank will likely be installed in your basement or garage, but a tankless water heater gives you more options. You can install it on the wall in a closet or other tight space. There are even outdoor models. Rheem tankless water heaters have industry best side-to-side clearance which means they can fit into even tighter spaces.

What are some things to consider before purchasing a tankless water heater?

Tankless water heaters may or may not cost more money than a tank-style water heater. The main difference is in the installation. The installation of a tankless unit is more complicated. However, because tankless water heaters are energy efficient, many local utility companies offer rebates and incentives which helps offset the higher installation costs. Check with your local utility company for eligibility.

When are the outdoor models a good option?

Outdoor tankless water heaters are a great option for warmer climates, especially if you are lacking wall space inside your home. They are easy to install as they don’t require venting and can fit almost anywhere with easy access to plumbing lines and electrical outlets.

How efficient is a tankless water heater?

Our residential tankless gas water heaters are ENERGY STAR-certified and the ultra low NOx (ULN) units dramatically reduce greenhouse emissions.1 Since a tankless only heats hot water when you are using it, you reduce energy waste. With the water saving setting enabled, you can save up to 1,000 gallons of water per year.2

tankless water heater installHow should a tankless water heater be installed?

We always recommend having a plumber install your water heater. They are up to date on the latest installation methods. You can find a local plumber to complete the install.

Where can I go to find more information about tankless water heaters?

You can access all of our tankless blog posts to learn more about them.

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1Lower greenhouse gas emissions and carbon footprint as compared to standard tank-type gas water heater. 2Savings based on DOE test procedures; available only on models featuring a -1 or -2 in the model.