InspectAPedia ®

Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice
InspectAPedia
Home
| Air
Conditioning
| Electrical | Indoor
Environment
| Exteriors | Heating | Home
Inspection
| Insulate
Ventilate
| Interiors | Mold
Inspect/Test
| Plumbing
Water
Septic
| Roofing | Structure | Contact Us
Directory of Professionals to Inspect or Test a Building


Mobile Phone/PDA website viewMobile View
HEATING SYSTEMS
PLUMBING TOPICS
HOT WATER HEATERS
AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
  Electric Shower Heaters
  High Efficiency Water Heaters
  Indirect-fired Water Heaters
  Instantaneous Water Heaters
  Multiple water heaters in parallel
  Multiple water heaters in series
  Range Boiler Water Heaters
  Side Arm Coil Water Heaters
  Solar Water Heaters
  Tankless Coil for Hot Water
  Tankless Water Heaters
    Guide to Tankless Water Heaters
    Operation & Characteristics
    Problems & Defects
    Hot Water Delivery Speedup
    Installation Requirements & Costs
    Should I Convert to a Tankless Heater?
    Calculate Water Heater Requirements
    Capacities of Tankless Water Heaters
    Life Expectancy & Applications
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
CARBON MONOXIDE/DIOXIDE
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CLOGGED PIPING & Hot Water Flow
ELECTRIC WATER HEATERS
GAS FIRED WATER HEATERS
  DRAFT HOODS - gas fired
  Gas BTUH & Cubic Feet
  Gas Conversion LP Natural Gas
  GAS PIPING, VALVES, CONTROLS
  SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
HOT WATER IMPROVEMENTS
HOT WATER DELIVERY SPEED UP
HOT WATER QUANTITY IMPROVEMENT
  Alternative Hot Water Sources & Methods
  Anti-Scald Valves & Hot Water Quantity
  CLOGGED PIPING & Hot Water Flow
  Extra Tanks to Increase Hot Water
  Insulate Hot Water Piping
  Insulate Hot Water Tank?
  Larger Diameter Water Supply Piping
  Temperature of Hot Water is Too Low
INDIRECT FIRED WATER HEATERS

NO HEAT - NO HOT WATER: HEATER DIAGNOSIS
NOISES COMING FROM WATER HEATER
ODORS IN WATER
OIL FIRED WATER HEATERS
  DRAFT REGULATORS - barometric dampers
  OIL BURNERS
  OIL BURNER NOISE SMOKE ODORS
  OIL PIPING
  OIL TANKS
MIXING VALVES
PLASTIC HEATER VENT
RANGE BOILERS
RELIEF VALVES - TP Valves on Boilers
Relief Valves - Water Heaters
SAFETY DURING HEATING INSPECTION
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SOLAR HOT WATER HEATERS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
TANKLESS COILS
  Clogged Piping / Tankless Coil & Hot Water Flow
  Mixing Valves
  Tankless Coil Leaks
  Tankless Coil Hot Water Increase
TANKLESS WATER HEATERS
Temperature Pressure Relief Valves - Water Heaters
Water Heater Noises
WATER HEATER PROPERTIES
  Electric, Gas, Oil Water Heater Efficiency
  Water Heater Life Expectancy Comparisons
  Water Heater Operating Cost Comparisons
  Water Heater Purchase & Maintenance Costs
  Water Heater Water Quantity Comparisons
  Water Heater Recovery Speed Comparisons
  Water Heater Safety Comparisons
Water Heater Scale - De-Liming Procedures
WATER QUALITY TESTS, CONTAMINANTS, TREATMENT
WATER QUANTITY IMPROVEMENT
WATER QUANTITY USAGE GUIDE
WATER SOFTENERS

More Information

InspectAPedia.comInspectAPedia ® Home & Site Map
InspectAPedia Blog - News Updates
Air Conditioning & Heat Pumps
Bookstore
Electrical
Environment
Exteriors
Heating
Home Inspection
Insulate Ventilate
Interiors
Mold Inspect/Test
Plumbing Water Septic
Roofing
Structure
Accuracy & Privacy Policies
Contact Us



Tankless water heater (C) Carson DunlopOwner's Guide Converting to a Tankless Water Heater

Also called Demand Water Heaters or Instantaneous Water Heaters
InspectAPedia®  -    

  • An owner's guide to tankless water heaters - hot water on demand
  • Tankless water heaters = demand water heaters = instantaneous water heaters
  • Detailed explanation of how tankless hot water heaters work, what they cost, what are their operating characteristics, pro's and con's.
Our site offers impartial, unbiased advice without conflicts of interest. We will block advertisements which we discover or readers inform us are associated with bad business practices, false-advertising, or junk science. Our contact info is at InspectAPedia.com/appointment.htm.

Here we discuss the conversion from conventional hot water heaters to use of tankless water heaters, also called instant water heaters or "on demand" water heaters. Readers should also see ALTERNATIVE HOT WATER SOURCES to distinguish among these types of hot water producing systems.

The original text of this article was provided courtesy of Carson Dunlop - that text has been edited and may not entirely reflect CD's views. Page top sketch of a point of use tankless water heater courtesy of Carson Dunlop. Our OPINION is that readers looking for plenty of hot water heated efficiently should also consider the heater we describe at Indirect-fired Water Heaters.

© Copyright 2009 Daniel Friedman & Carson Dunlop Associates, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use the links at page left to navigate this document or to go to Other Website Topics. Green links at left show where you are in our document & website.

Should I Convert my Hot Water Supply to a Tankless Water Heater?

OPINION:

Most of us are familiar with the traditional-style water heater - that big thirty- to sixty-gallon tank taking up space in the basement near the furnace or boiler. These water heaters have served us well with few improvements for decades, but a different breed of water heater has been in use for many decades in Europe and Latin America, and has seen less widespread but growing popularity in the U.S. - the tankless water heater.

The energy-conscious world in which we live has turned its attention to the water heaters of old and has identified two potential areas of improvement. The first is that traditional water heaters are not very efficient at converting the energy in fossil fuels into hot water. Over the last twenty years, furnace and boiler technology has improved the efficiency of home heating, but water heaters have not kept pace, even though the same technology can be applied.

The second possible improvement that can be made to water heaters has to do with the storage of hot water. Traditional water heaters use fuel to heat water inside the tank. If the water is not used, it cools to the point that it must be heated up again.

The result is that we are constantly keeping a large volume of water at a high temperature, even if we are not planning on using any of it in the next little while. This means that while we are sleeping or at work, our water heaters are burning fuel or consuming electricity keeping a whole tank of water hot.

This is not a problem in the winter, when the heat loss from the water heater helps keep the building warm. It is a challenge in the summer, when the building is already warmer than we want. Tank-type water heaters can increase air conditioning costs.

As the name suggests, tankless water heaters have no tank, and therefore no storage capacity at all. When the faucets and fixtures in the home are sitting unused, the water heater is dormant. When somebody turns on a hot water faucet, the tankless heater swings into action.

These units use more powerful burners than conventional water heaters to heat relatively small amounts of water. The result is that the water is heated much more quickly than in an older system and this hot water can be immediately delivered to the fixtures.

A significant advantage of this system is that you can't empty all of the hot water out of the tank because there is no tank - just continuous hot water.

Also, since there is no tank, the water heater itself is much smaller. In most cases, these units are wall-mounted, so we not only do we have improved efficiency, reduced fuel costs, and unlimited hot water, but more free space in our basements!

While this all sounds good so far, there is a reason that everybody isn't switching over right away.

Conventional water heaters, due to their simplicity, are relatively inexpensive, while tankless water heaters are more expensive to purchase.

Their complexity also means that maintenance and repairs can be more expensive as well, and while tankless units have been in use around the world for many years, the rapidly evolving technology and our cold climate means that we don't have a great idea how long the typical life expectancy will be in North American homes.

Still, when it comes time to change your water heater, consider getting rid of that big tank and going tankless.

Share this Article      

...

Technical Reviewers & References

  • Daniel Friedman - principal author/editor of the InspectAPedia® Website
  • InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
  • Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
  • Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

  Tankless Water Heaters
    Guide to Tankless Water Heaters
    Operation & Characteristics
    Problems & Defects
    Hot Water Delivery Speedup
    Installation Requirements & Costs
    Should I Convert to a Tankless Heater?
    Calculate Water Heater Requirements
    Capacities of Tankless Water Heaters
    Life Expectancy & Applications

  • Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
  • Consumer Reports offers an article on the efficiency versus the economy of tankless water heaters - see http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/water-heaters/tankless-water-heaters/overview/tankless-water-heaters-ov.htm
  • Bosch Tankless Water Heaters - http://www.boschhotwater.com/
  • Chromolite Tankless Water Heaters
  • Bradford White Everhot Tankless Water Heaters - Bradford White offers this step by step hot water retrofit installation file (large, slow PDF) - www.bradfordwhite.com
  • Eemax Tankless Water Heaters - http://www.eemaxinc.com/
  • Noritz Tankless Water Heaters - http://www.noritz.com/
  • Rheem Tankless Water Heaters - http://www.rheemtankless.com/content/
  • Rinnai Tankless Water Heaters - http://www.rinnai.us/tankless-water-heaters/
  • Stiebel Eltron Tankless Water Heaters - http://www.stiebel-eltron-usa.com/
  • Takagi USA Tankless Water Heaters - http://www.takagi.com/
  • Titan Tankless Water Heaters - http://www.titanheater.com/
  • U.S. Department of Energy on Tankless Water Heaters - http://apps1.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=12820

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

  • Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
  • ...
HEATING SYSTEMS
PLUMBING TOPICS
HOT WATER HEATERS

More Information


InspectAPedia® Home & Site Map
Air Conditioning & Heat Pumps
Bookstore
Electrical
Environment
Exteriors
Heating
Home Inspection
Insulate Ventilate
Interiors
Mold Inspect/Test
Plumbing Water Septic
Roofing
Structure
Accuracy & Privacy Policies
Contact Us

More Information on Building Diagnostic Inspections and Repairs

    ...
InspectAPedia.comInspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.
GO TO the MOLD and INDOOR ENVIRONMENT INFORMATION CENTER for in-depth advice on avoiding testing for or cleaning up mold and other indoor environmental hazards, odors, gases, contaminants
The Mold Information Center:
What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems
GO TO MOLD TEST KITS: This expert-recommended mold test kit is cheap and yet top performing *IF* you use a competent analysis laboratory!
Use this simple, economical mold test kit
by following our instructions on how to collect and mail mold samples to our lab
GO TO IAQ/MOLD-TEST LAB SERVICES: Mold, Pollen, indoor air quality, field and laboratory services by an expert.Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.
GO TO our PRE PURCHASE BUILDING INSPECTION SERVICES: Authoritative information for home buyers and home owners is included with your inspection.
Building Inspection, Problem Diagnosis
, Forensic Investigation & Testing, Repair Consulting

CONTACT Daniel Friedman - Dan is a senior ASHI home inspector, nationally recognized expert on building inspection, building failures, and sick building investigation
Contact Daniel Friedman for website content suggestions or for fee-paid consulting

03/10/2009 - 02/02/2009 - InspectAPedia.com/plumbing/Tankless_Water_Heaters4.htm - © 2009 - 1988 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark