ACHR News
search
Ask ACHR NEWS AI
cart
facebook twitter instagram linkedin youtube
  • Sign In
  • Subscribe
  • Sign Out
  • My Account
ACHR News
  • NEWS
    • Breaking News
    • New HVAC Products
    • Featured Products
    • Manufacturer Reports
    • HVAC Data
    • Legislation
    • ACHR NEWS Centennial
  • RESIDENTIAL
    • Air Conditioners
    • Furnaces
    • Residential Heat Pumps
    • Ductless
    • Residential IAQ
    • Testing, Monitoring, Tools
    • Components & Accessories
  • COMMERCIAL
    • Air Handlers
    • Rooftop Units
    • Chillers and Cooling Towers
    • Commercial Heat Pumps
    • Boilers and Hydronics
    • VRF/Ductless
    • Commercial IAQ
  • REFRIGERATION
    • Refrigerants
    • Refrigerant Regulations
    • Leak Management
  • CONTRACTOR PRO
    • Geothermal
    • Homeowner Study
    • VRF and VRV Ductless
    • Unitary Trends
  • EDUCATION
    • Training and Education
    • Business Management
    • Service and Maintenance
    • Continuing Education
    • Market Research >
      • HVAC Brand Awareness Report
      • VRV, VRF, VRVZ Report
      • Unitary Trends Report
      • Water Heat Professionals Report
    • Webinars
    • Sponsor Insights
    • eProducts Info
    • White Papers
  • EVENTS
    • HVAC Contractor Forum
    • Industry Events and Webinars
  • MEDIA
    • Videos
    • AHR Expo 2025 Videos
    • Podcasts >
      • ACHR News Podcast
      • HARDI Podcasts
      • AHR Expo Podcasts
      • ACCA Podcasts
    • Interactive Spotlights
    • Quizzes
    • eBooks
    • HVAC Talkback
  • HVAC GROUP
    • ACHR NEWS >
      • Current Issue
      • Digital Edition
      • Subscribe
    • Distribution Trends
    • SNIPS NEWS >
      • Join SNIPS NEWS
    • Engineered Systems News >
      • Join ES News
    • HVACR Directory
    • Contests
    • Newsletters
    • Contact
    • Advertise
    • My Account

Again with the ‘Sizing'

By Rich Schuster
January 14, 2011

Welcome back! Alright, enough small talk already, let’s get down to business. What do you know about tankless water heaters? Just the gas fired units, natural or LP; we’ll leave the electric, diesel, and nuclear powered ones for another time. Well? O.K. yes, they are more expensive. And yes, most of them hang on the wall, good. Anyone else? No? How about BTUs; any ideas? Well, since they make hot water so quickly, they must have an awful lot of fire in that little box, and in fact they do. Many will fire up to 199,000 BTUs, sometimes even more. So, just for comparison’s sake, do you recall how many of those British Thermal thingies a regular 40 gallon heater uses? Jake says “three”; anyone agree? Good; Jake, go sit in the corner.

Most residential water heaters use around 40,000 BTUs to get the job done. So, without getting into a discussion about which actually uses more or less gas in the long run, let’s just toss around some of the most common installation problems that we’re seeing out there. Actually, the most common are indeed all the same. Ninety percent of all tankless water heater installation problems are due to…. gas pipe sizing, of all things! I know the drill; “ahhh, yeah this one must have a defect from the factory”, and “Those things suck. They never work”. More likely though, somebody didn’t read the directions, or was texting their girlfriend during that part of the class.

But what about the common sense? Does it make sense that this unit that uses FIVE TIMES as much gas would use the same size pipe? Take out your gas pipe sizing chart that you keep in your shirt pocket and refer to on a daily basis, and try it here. Do ya see what I’m talkin’ about? You’re not even close, so stop blaming the equipment; it’s your helper’s fault, of course. Now, the capacity of the gas meter…..

Share This Story

Rich Schuster has worked in many phases of the HVAC and plumbing industries since 1991, from apprentice to general manager in the contractor segment, and later as a rep for a large HVAC wholesaler. He has written two books with a focus on installation training basics, and can be reached at richardjschuster@gmail.com.

Recent Comments

Small Fixes That Made a Big Difference

Small Fixes That Made a Big Difference

Great article....

Increase in decorative HVAC air distribution products due to tariffs

Nice job Mr. Zollinger! I can see why...

Blog Roll

Guest Blog

Opinions

Editors Blog

Subscription Center
  • Create an Account
  • Start a Subscription
  • Manage My Account
  • Sign Up for Newsletters
  • Visit Customer Service
  • Update Preferences

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to The News audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of The News or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • An illustration shows a house with a geothermal heating system. Pipes are depicted running underground.
    Sponsored byClimateMaster

    Residential Tax Credits Are Ending, But Demand Continues

  • Piggy Bank
    Sponsored byWatercress Financial

    Energy Prices, Inflation, and HVAC: What Today’s Homeowners Care About

  • Refrigerated Food
    Sponsored bySolstice Advanced Materials

    R-455A Refrigeration: A Cold Storage Solution for the Future

Popular Stories

price-raising-practices.jpg

Rising Costs Force Contractors to Take a Harder Look at Pricing

New-HVAC-Equipment.jpg

Amended Complaint Filed in HVAC Price-Fixing Lawsuit

DOE-sign.jpg

HVAC Groups Support DOE’s Rulemaking to Cut Energy Efficiency Mandates

Data-Center-Inspection.jpg

Can HVAC Train Enough Technicians for the Data Center Boom?

HARDI lolgo navy

HARDI Distributors' Sales Down Nearly 5% in May

View The ACHR NEWS
Centennial Anniversary Timeline

The ACHR News Timeline Chart
Submit a Letter
Submit a letter to our editors.

Events

November 6, 2025

Next-Gen Data Center Cooling: HVAC Innovation and Real-World Solutions

On Demand As AI workloads and high-density computing push traditional cooling methods to their limits, the data center industry is accelerating the adoption of next-generation HVAC technologies.

July 22, 2026

Designing VRF Systems Using A2L Refrigerant

In this session, we will cover how to design VRF systems for the U.S. market using new A2L refrigerants. These systems provide an advanced zoning solution by using inverter technology to deliver precise heating and cooling control across multiple zones and spaces.

View All Submit An Event

Poll

Summer Staff

Are you fully staffed for the summer season?
View Results Poll Archive

Products

BNI Mechanical/Electrical Square Foot Costbook, 2026 Edition

BNI Mechanical/Electrical Square Foot Costbook, 2026 Edition

See More Products
Designing Systems Using A2L Refrigerant - Free Webinar - 7/22/2026
×

Sign Up. Stay Informed.

The #1 trusted source for the HVACR industry since 1926

SUBSCRIBE
  • RESOURCES
    • Advertise
    • Contact Us
    • Advisory Board
    • Classifieds
    • Submit a Letter
    • Directories
    • Store
  • ACCOUNT CENTER
    • Create an Account
    • Start a Subscription
    • Manage My Account
    • Sign Up for Newsletters
    • Visit Customer Service
    • Update Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2026. All Rights Reserved BNP Media, Inc. and BNP Media II, LLC.

Design, CMS, Hosting & Web Development :: ePublishing