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How Much Does it Cost to Install a Tankless Water Heater in Phoenix?

March 06, 2019

If it’s time to replace your old water heater or buy a tankless water heater for the first time, you want to know how much it’s going to cost you.

Unfortunately, the only way to determine the exact cost of installation is to have an expert plumber assess your home and heating needs.

However, we can tell you that the average cost to install a tankless water heater in Phoenix ranges from $1,000 to $2,700+.

This price range is dependent on a few factors, including:

  • Size (flow rate) of the unit
  • Water heater type
  • Fuel type (gas or electric)
  • Plumber you hire

We know—it’s a lot to consider, and deciding what is best for your home can be confusing. Below we’ll walk you through the details of each of these cost factors to help you decide which is best for your Phoenix home.

Sound like too much work? Our expert team of plumbers can assess your home, needs and budget and provide you with a few tankless water heater installation options that are best for you.

Price factor #1: Size (flow rate)

Unlike tank water heaters, tankless water heaters don’t hold water but heat water as it flows through a heat exchanger. Because of this, the “size” of a tankless water heater is determined by flow rate, the number of gallons per minute (gpm) of hot water the heater can provide.

The larger the flow rate, the more a water heater will cost to install.  

The flow rate you need for your home will depend on the total flow rate of the appliances you use at the same time.

For example, if you want to use the kitchen sink at the same time the washer is running, you will need a flow rate that equals or exceeds the flow rate of your kitchen sink + the flow rate of your washing machine.

The most accurate way to do this is to have a plumber come to your home and assess this for you.

However, if you want a rough estimate, you can add the average flow rates of the appliances you use simultaneously. Here are the flow rates of a few common water appliances.

  • Bathroom faucet: 0.5–2.5 gpm
  • Showerhead: 1–3 gpm
  • Washing machine: 1.5–2 gpm
  • Dishwasher: 1–2.5 gpm

Price factor #2: Water heater type

When it comes to tankless water heaters, there are two main types:

  1. Whole home units
  2. POU units

Whole home tankless unit

Whole home units provide hot water to all plumbing fixtures in your home.

Point-of-use (POU) units

Unlike whole home units, POU units provide hot water to a single appliance or area (like a bathroom or laundry room).

How do I determine which is best for my home?

Great question! Many homes only need a whole-home unit. However, you may need to pair a whole-home unit with one or several POU units if your home has:

  • Hot water appliances that are too far from the whole-home unit
  • Appliances that have high flow rates

To determine the number of units you need for your home, a plumber will need to come and assess your hot water appliances. The more units you need, the more expensive your installation will be.

Price factor #3: Fuel type

Gas tankless water heaters are more expensive to install but are cheaper to operate on a monthly basis.

Let’s break down the installation costs of each.


If you already have gas lines, this is a great option. If not, gas installations can be very expensive because of additional costs like:

  • Installing a gas line: If your home doesn’t have a gas line, it will need to be installed. Installing a gas line can increase your installation cost by $3,000+.
  • Extending a gas line: If your home has access to natural gas but there is not a line close enough to your tankless water heater, the gas line will need to be extended, raising the installation cost.
  • Venting: Gas water heaters actually produce gases through the combustion process, and need to vent to the exterior so these gases can be expelled outside. If you haven’t had a gas water heater, a plumber will likely need to cut through walls to install this venting, increasing your installation cost.


Electric water heaters are cheaper to install because they don’t require the additional infrastructure that gas heaters do. One additional cost you might see with an electric water heater is:

  • An electrical panel upgrade: Your home’s electrical panel may not be powerful enough to support the load of a new water heater. If your electrical panel needs to be upgraded, it could cost a couple thousand dollars.

Price factor #4: Plumber you hire

The bottom line: You will pay more for a more experienced plumber.

Our take? It’s worth it.

Plumbing installations can be complicated, and you want someone who has the skills and knowledge necessary to do the job correctly and safely.

A few tips for finding a great plumber are:

  • Verify their license and insurance. You can do this by either checking for their license number on their website or by checking out the BBB (Better Business Bureau). All companies that have a profile on the BBB have a valid license and insurance.
  • Make sure they have good reviews. Check sites like: 
  • Get a written estimate. If a contractor won’t provide you with a written estimate, it should be a warning sign. A written estimate protects you from any unknown or surprise costs and helps you avoid any discrepancies in cost after your installation has been completed. 

Ready to install a tankless water heater? Hire a Phoenix tech!

One of our expert plumbers will provide a free in-home estimate and ensure that your tankless water heater is installed correctly.

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