Tankless Water Heater Introduction

Hot Water on Demand

Tankless Hot Water Heaters Respond Quickly to your Demand for Water for Showers and other Water Uses and Do Not Quit until you Turn off the Flow.

For a Larger Family this is the only way to not run out of Hot Water, even when there are more than 1 or 2 Showers being used at the same time.

Tankless Heaters are Not for all Homes. Electric Only Homes may not benefit plus there are other factors to consider. This Article should help you decide if Tankless is for You.

Do it Yourself

DIY is not suggested and some Manufactures may not Honor the Warranty if it was not Installed by a Professional. I have read more than 150 Reviews that were DIY installs, I would say most had Good Outcomes just be sure to Read and understand the Installation Requirements. If you are not a Confident Plumber the Call a Pro.

The Difference

The Cost to Replace your Storage Tank Water Heater with a Tankless Heater is more Expensive. The Higher Costs is due to Longer Installation Time and Additional Parts.

Average Prices for the 3 most Popular Brands of Tankless Heaters w/o Installatation Range from $550.00 to $1,800.00 or more in some cases.

Installation Time

Average time to Remove and Replace the Hot Water Storage Tank is 1 to 3 hours.

Install time for a Tankless Heater could be Double. A Licensed Plumber with Experience in Converting a Storage Heater with a Tankless should do it in the Shortest Time Frame. Some say it can be done in 3 to 4 hours for a Simple Install in a Convenient Location.


Don't undersize just to save a Few Dollars. Determine the Maximum Gallons Per Minute (gpm) that could be used at any one time. Knowing the Hot Water Demand is Part of the process in Determining the Size of a Tankless Unit. see Our Flow Rate Chart for Showers & Faucets in Our Water Heaters Article. link below

Ground Water Temperature is important when Sizing, so you can Calculate the Temperature Rise needed to support 1, 2 or 3 Showers plus other Faucets in the Home that may be operating at the same time. Chart below


The UEF is a Metric used to Determine the Energy Efficiency of a Water Heater. The Higher the Number the More Efficient the Unit. Each Unit has its own Efficiency Rating, that could Range between .80 to .98.

BTU Rating

BTU is British Thermo Unit or Heat required to raise 1 Pound of Water 1 Degree in Fahrenheit or the Size of the Burner. Electric Heaters are Rated in Wattage not BTU. The Equivalent is 1 Watt produces 3,413 BTU

Condensing vs. Non-Condensing

Condensing Units Pass the Cooler Inlet Water Through the Secondary Portion of the Heat Exchanger at the Top of the Unit Where the Hot Exhaust is Collecting.

This Pre-Heats the Water plus the cooler Water Helps Cool the Exhaust So a PVC Pipe for the Vent can be used. Condensate will Form here and must be Drained to an appropriate Drain.

Non-Condensing Units will Require a Metal Vent Pipe. Some Tankless Water Heaters will Require a Special Vent Pipe the will Carry the Air needed for Combustion to the Unit.

Gas Volume Requirement

To Supply a Burner that is Rated at 199,000 BTU's requires a certain Volume of Gas, Propane or Nat Gas. You may not be able to get that Volume through a long 1/2" Supply Pipe. At some point you should consult your Gas Provider to be certain your Meter, Regulator and Pipe can supply the Volume of Gas required to properly operate a Tankless Water Heater.

Electrical Supply

Tankless Water Heaters will require a 110 or 220 volt Power Supply for the Operation of the Gas Control Valve and some Internal Blowers.

Water Sofener

Water Softeners in Hard Water Locations are recommended. The Minerals can Build Up inside the Exchanger and reduce the Performance over time. Most Tankless Water Heater Manufactures recommend a De-Scaling Procedure at least once a year even with a Softener.


Choose a Location for the Tankless Hot Water Heater that will conceal that Extra Noise they make. The Burner of a Tankless Unit Burns a High Volume of Gas and therefore will make noise. if you Plan on adding a Re-Circulation System to your Tankless Heater, that is added noise, some complain about the noise the Water makes moving through the Pipes.


Manufactures of Tankless Water Heaters have Limited Warranties. Read the fine Print, None are trying to hide anything in the Warranty terms. That is why you should read and understand them. A Warranty example is 10/5/1, Breaking it down to mean 10 years for the Heat Exchanger, Parts and Components 5 years and Labor for 1 year. All Manufactures have Exclusions, you should understand them upfront and not think you have unconditional coverage for 10 or 12 years

Flow Rate Chart in Gallon per Minute
Appliance Energy Star Non Energy Star
Dish Washer 6 gpm 16 gpm
Washing Machine 14 per load 20 per load
Kitchen Faucets N/A 2.0 gpm
Bath Faucets 1.5 gpm 2.2 gpm
Shower Heads 2.0 gpm 2.5 gpm
Custom 7 foot 4 inch Shower

Sizing Example

Calculate Temperature Rise Needed. 1st use the Heater Temperature Setting (120°) 2nd Subtract Ground Water Temp, the Result equals amount of Rise Needed. 3rd Determine the Amount of Water that could be used at the Same Time (GPM) Then Compare your GPM Calculation to the Specs of the Heater you want to Install. We Compared Takagi Models Directly, a Time Consuming Procedure, we will compare the other 2 when Possible.

Comment Below

Internal Links

Induction Cooktops

Hot Water Circulation

Garbage Disposals

Cleaning Disposals

Takagi Tankless

Rheem Tankless

Rinnai Tankless

Water Heating Types

Like this Article, you can give us a Thumbs just click on the Icon. It's anonymous and we will Thank You.

Thank You

“Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time”
Thomas Edison

© Copyright 2023 YPRemodel.com. All rights Reserved. This material may not be Published, Broadcast, Rewritten or Redistributed without written Permission.


Required fields are marked * We Do Not Sell or Use Your Email Address, We Discard your Information after a Communication is Finished. Enter a Subject like Tankless Water Heaters

Your Comment has been sent. Thank you!