• Ao Smith Water Heater Troubleshooting Ma…
• Ao Smith Water Heater Troubleshooting Guide

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Need product support? Search for support documentation for your A. Smith Signature Series water heater. Smith Water Heater Age or Manuals AO Smith Water Heater Age, Manuals, Installation, Repair. National water heaters & Perma-Glas water heaters. This handbook contains supplemental information to the Residential Gas and Electric instructional manual. AO SMITH GAS & ELECTRIC WATER HEATER SERVICE MANUAL PDF. Smith’s new proprietary electronic water heater control provides precise + or – 1° temperature control that is ideal for industrial and food service applications where exact temperatures are needed. The Operating Set Point is adjustable from 90°F/42°C to 190°F/88°C. The factory setting is 120°F/49°C. Smith offers a wide range of water heaters. Through constant innovation, at production level and application level, A.O. Smith maintains its leading position in the market. This applies both to the choice of materials and components used in the manufacturing process, as well as to the efficiency of the finished products.

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A.O. Smith Water heater age decode key & water heater manual sources.

Age decoding guid for water AO Smith water heaters, manuals, repair & maintenance guides.

We give contact information for AO Smith water heater, geyser, cylinder, calorifier manufacturers and for water heater installation, operation, & troubleshooting manuals.

Aug 28, 2018  Signature 40 Gallon Tall 6 Year Limited 34000 Btu Natural Gas Water Heater. A o smith bth 500a user manual 8 pages jpg ao smith bth 150 specs state water heater hot surface ao smith 50 gallon water heater reviews electric manual a 0 smith water heaters icapish co a o smith water heater cyclone bfc 30 installation manual.

We include a table of common error codes given on some models of A.O. Smith water heaters.

Our photo at page top shows an oil fired water heater with a backpressure problem and other safety concerns like a missing extension tube on that relief valve, and maybe a missing draft regulator and perhaps an oil line that is not protected from damage.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

A.O. Smith Water Heater Age Decoding Tips

A.O. Smith Water Heater Age Determination - reader comment: (May 11, 2012) AO Smith employee said: To tell the age of any AO Smith water is the first 4 numbers.

The first 2 are the year and the second 2 are what week it is. I work in the Q.C. Department there and make the serial plates all the time. Hope this information helps some people out - A.O.S. employee.

Current AO Smith water heater date code

Ser# YYWW123456 example 1604123456 decodes to YY=Year=2016 and WW=Week No. 04 of that year.

However on some AO Smith water heaters, particularly older models, you'll see a confusion of letters and numbers in the serial number that may be decoded into manufacturing date as shown below.

Older AO Smith water heater date codes

Ser# YYWW123456 - exampl: Ser# 9902123456 decodes to year 1999 and the week 02 - or early January. This A.O. Smith water heater date of manufacture code has been used since 2008.

Ser# MMYY1234567 - example: Ser# 03991234567 decodes to March 1999 this older style AO Smith water heater date code decodes as shown where MM = month and YY = 2 digit year.

Ser# MYY1234567 - example Ser# B0112344567 decodes to February 2001: the first letter encodes the month using A - N for January - December (the letter I is not used) and the second two digits encode the year.

Ser# FB00A123456 decodes to F=Factory code, B=month code using A - N for January - December (the letter I is not used) and the next two digits encode the year.
- example: Ser# GB92-03123456-789 decodes to Factory ID=G, Month=B or February, Year=92 or 1992.

Other AO Smith water heaters that may be sold under different brand names include Glascote water heaters, National water heaters & Perma-Glas water heaters.

Contact Information & Service Manuals for AO Smith Water Heaters

Photo: A.O. Smith water heater data tag detail showing the water heater serial number:

• A.O. Smith Water Products, A. O. Smith Water Products500 Tennessee Waltz ParkwayAshland City, TN 37015USA, Tel: 800-527-1953.
  Website: http://www.hotwater.com/water-heaters/ - readers can find their type and model of AOS water heater and then find all of the documents concerning that model
  AO Smith water heater manufacaturer's water heater age page: https://www.aosmithinternational.com/manufacturing-date-device/
  A. O. Smith Corporation is one of the world's leading manufacturers of residential and commercial water heaters and boilers, offering a comprehensive product line featuring the best-known brands in North America, China, and India.
  The company was founded in 1874 in Milwaukee, Wisconsin where today the company is headquartered. - retrieved 2018/02/23, original source: https://www.aosmith.com/about/

Photos: Above: an A.O. Smith water heater installed, and the product packaging label data for that new AOS electric water heater.

Below: the data tag for this new A.O. Smith electric water heater.

The serial number for this A.O. Smith water heater is ME98-0041362-917

I decode this to E = May and 98 = 1998. We purchased this water heater as new old stock in 2015 - it was the last heater of this model series in stock at the local Poughkeepsie supplier.

[Click to enlarge any image]

AO Smith Water Heater Manuals & Troubleshooting Guides

• A.O. Smith CONDENSING WATER HEATER TROUBLESHOOTING GUIDE [PDF], (2011) A.O. Smith Water Products Company500 Tennessee Waltz ParkwayAshland City, TN 37015Toll Free: 1‐877‐737‐2840
• A.O. Smith PROMAX® ELECTRIC WATER HEATER 30 GALLON MANUAL [PDF] ProMax® electric water heaters for ProLine® water heater models ENT-30 ENT-40 ENTB-50 ENT-50 ENT-55 ENSB-30 ENS-30 ENS-40 ENS-50 ENLB-30 ENL-30 ENLB-40 ENL-40
• A.O. Smith PROLINE® ELECTRIC WATER HEATER [PDF] ProLine® electric water heaters
• A.O. Smith PROLINE® 50 Gallon LOWBOY MOBILE HOME WATER HEATER MANUAL [PDF] Proline Electric water heaters for models MHEW2-30L-035DV MHEW2-30H-035DV MHEW2-40R-035DV MHEW2-30L-030DV MHEW2-30H-030DV MHEW2-40R-030DV
• A.O. Smith RESIDENTIAL GAS & ELECTRIC WATER HEATER SERVICE HANDBOOK [PDF] retrieved 2017/11/17, original source: https://www.hotwater.com/lit/training/320991-000.pdf
  This manual covers residential gas fired water heaters that are atmospherically vented and use a thermocouple as their electrical source, and residential electric water heaters having one or two heating elements and common wiring configurations.
  Excerpt:
  The information contained in this handbook is designed to answer commonly faced situations encountered in the operation of the Residential Gas and Electric product line and is not meant to be all-inclusive.
  If you are experiencing a problem not covered in this handbook, please contact the A.O. Smith Technical Information Center at 1-800-527-1953 or your local A.O. Smith Water Products Company representative for further assistance.
  Additional information is also available on the web site www.aosmithwaterheaters.com. This handbook is intended for use by licensed plumbing professionals and reference should be made to the instructional manual accompanying the product.
  This handbook contains supplemental information to the Residential Gas and Electric instructional manual.
• AO SMITH GAS & ELECTRIC WATER HEATER SERVICE MANUAL [PDF] retrieved 2018/04/10, original source: AO Smith www.hotwater.com/lit/training/320991-000.pdf
• AO SMITH ELECTRIC WATER HEATER WIRING INSTRUCTIONS [PDF] A. O. Smith Water Products 500 Tennessee Waltz Parkway Ashland City, TN 37015 USA Phone: 800-527-1953 A. O. Smith products, technical support, warranty or service needs Website: www.hotwater.com
• A.O. Smith, INSTRUCTION MANUAL, GAS WATER HEATERS MODEL GDV GDVT [PDF] A.O. Smith Water Heaters, 500 Tennessee Waltz Parkway, Ashland City, TN 37015 USA, Tel: 1-800-433-2545 Website: www.aosmithwaterheaters.com Email: parts@hotwater.comretrieved 2018/05/04, original source: www.hotwater.com/lit/im/res_gas/186589-000.pdf
• AO SMITH GAS WATER HEATER OWNERS MANUAL [PDF]
• AO SMITH GAS WATER HEATER PARTS LIST [PDF]
• AOS Bulletin 13 WATER HEATER MINERAL BUILD-UP [PDF] retrieved 2017/11/17 original source: https://www.hotwater.com/lit/bulletin/bulletin13.pdf
• AOS Bulletin 14 HEATER ALUMINUM HYDROXIDE [PDF] retrieved 2017/11/17 original source: https://www.hotwater.com/lit/bulletin/bulletin14.pdf
• AOS Bulletin 15 HEATER CONDENSATION [PDF] retrieved 2017/11/17 original source: https://www.hotwater.com/lit/bulletin/bulletin15.pdf
• AO SMITH WATER HEATER DE-LIMING INSTRUCTIONS [PDF]
• AOS Bulletin 11: WATER HEATER WATER HAMMER [PDF] retrieved 2017/11/17, original source: https://www.hotwater.com/lit/bulletin/bulletin11.pdf
• AOS Bulletin 51 WATER HEATER PUDDLE ON FLOOR [at the water heater] [PDF] retrieved 2017/11/17, original source: https://www.hotwater.com/lit/bulletin/bulletin51.pdf
  and see AOS Bulletin 15 given above
• Also see TAKAGI WATER HEATER MANUALS, AGE, ERROR CODES

AO Smith Water Heater Standard Error Codes

If your AO Smith condensing water heater code includes a circuit board or remote control it can show an error code. Contact your plumber or AO Smith technical support at the location given above in this article.

Watch out: your water heater model may use different codes or may provide error codes that are not given here. Therefore you'll want to consult the manual for your specific heater.

How to use the A.O. Simth water heater error code table above

Watch out: some water heater defects represent dangerous conditions, risking fire, explosion, or carbon monoxide poisoning or scalding hazards. Work on these heaters must be by a qualifed service professional.

See the water heater manual or troubleshooting manual for your specific water heater model for expanded detail about the meaning and the corrective steps for each of these error codes.

See A.O. Smith CONDENSING WATER HEATER TROUBLESHOOTING GUIDE [PDF], (2011) A.O. Smith Water Products Company 500 Tennessee Waltz Parkway Ashland City, TN 37015 Toll Free: 1‐877‐737‐2840

Also see TAKAGI WATER HEATER MANUALS, AGE, ERROR CODES - Takagi water heaters are distributed in North America by A.O. Smith.

Also see this TB-A028-06 - A. O. SMITH - FVIR INTELLI-VENT TROUBLESHOOTING CHART that gives LED status codes for the AO Smith Intelli-Vent™ control.

Question: troubleshooting the Combustion Chamber Temperature Sensor - TCO thermal switch on an AO Smith Water Heater

(Apr 9, 2018) john said:
Hello, I have a bit of a situation on my hands and I would really appreciate some help. Our Promax Plus water heater suddenly stopped working a few days ago so we ran to lowes and purchased a universal thermocouple.

When we took out the old thermocouple I noticed that it had a TCO while the universal one did not, no big deal i thought so i installed the new universal thermocouple and the pilot fired right up, literally.

This was yesterday. Well for the rest of the day the heater stayed on, again literally, but i figured it was normal since it was a new thermocouple. Fast forward to today and the furnace was still turned on. Turned on like when someone is taking a shower or is using hot water. Now i know this isnt normal and very dangerous so we turned off the heater and turned the gas to off.

So to summarize the heater stayed on after we replaced the thermocouple with a universal one with no TCO. Could the lack of a TCO in the new thermocouple have caused this or is it something else?

Reply: TCO Temperature Cut-Off thermal reset switch on an A.O. Smith Water Heater.

Below is A.O. Smith corporation's description of their thermal cutoff sensor on the thermocouple:

COMBUSTION CHAMBER TEMPERATURE SENSOR - The C3 Technology water heaters will come equipped with a thermal cutoff (TCO) device that is integral with the thermocouple. Temperature cutoff points range from 160°C to 200°C depending on model. The TCO is an automatic reset thermal switch.

When activated it will open the thermocouple circuit and shut off the main and pilot burner gas flow. The pilot would have to be relit after the TCO has had sufficient time to cool down (sensor is below 120 degrees F).

The TCO performs two primary functions:

• In the event of flammable vapor ignition inside the combustion chamber, it senses the corresponding increase in temperature and shuts off gas flow to the main and pilot burners.

• If excessive temperatures inside the combustion chamber indicate poor combustion due to a clogged LDO screen or inadequate air for combustion, the TCO will shut off gas flow to the main and pilot burners.

John, from the above you'll see that the absence of a TCO on a thermocouple would not be likely to force a burner to stay on. I think more-likely the thermocouple you installed is defective or is not properly installed. I've found, for example, occasional operating problems when the end of the thermocouple that screws into the gas valve is not properly seated.

Watchout: The situation you describe is unsafe. I would leave the heater off pending proper repair.

Reader follow-up:

I really appreciate your response. The heater has been off since yesterday and wont be turned on again until the problem is fixed. The installation itself was actually something that I was going to double check.

Someone suggested the thermostat be replaced, is a faulty thermostat a possibility? This seems unlikely since it was working fine before.

Reply: details of the TCO on an AOS water heater

(Apr 10, 2018) (mod) said:
John

When a gas fired water heater burner won't turn OFF indeed I suspect a bad temperature sensor or thermostatic control. That's because the thermocouple has a more narrowly-defined job: confirming that there is a proper gas flame. The thermocouple is intended to shut OFF the burner IF there is no gas flame - so as to avoid continuing to pour explosive gas, un-ignited, into the building.

It's a safety device focused on proper gas ignition.

If your burner has GOT proper ignition and is burning on continuously, AND if no hot water is being taken out of the tank, it'd make sense to look for a bad thermostatic control.

What's troubling of course is that I inferred from your question that previously the heater was not turning ON and you had no hot water.

Below is a photo of AO Smith's 160 deg TCO.

Also see this AO SMITH GAS & ELECTRIC WATER HEATER SERVICE MANUAL [PDF] at inspectapedia.com/plumbing/AO-Smith-Gas-Electric-Water-Heater-Service-Manual.pdf retrieved 2018/04/10, original source: AO Smith www.hotwater.com/lit/training/320991-000.pdf

Reader Comments & Q&A

On 2019-07-19 by (mod) -

Anon
Let me know which manual you're looking at - one of ours? And that'll make it easier for me to research its publication date.

On 2019-07-19 by Anonymous

Need publication date for owners manuals. No date on manuals, but identified as part numbers 184165-003 and 320388-001.

On 2019-07-07 by Caryn

We own a AO smith has water heater. It flashes six times but no hot water. We unplugged it. It went through four cycles but then just shuts down. Any ideas?

On 2018-12-25 by (mod) -

EG
You can turn off the water heater when leaving for several days or longer, and will save a little money - standby losses from modern water heaters are not very great.
Conventional wisdom is that one can reduce the cost of electric hot water, if you use hot water at fairly regularly times, by having have an electrician install an automatic timer that turns the heater off for periods when it will not be in use -

see TIMERS for ELECTRIC WATER HEATERS inspectapedia.com/Energy/Hot_Water_Heater_Timers.php
Interestingly, Elk and Auberg found that timers don't save much energy, but that where hot water use occurs at regular times, turning the heater down (or maybe off) after the last daily use can save money. Here is an excerpt:
It is apparent that for no-flow standby loss reduction, the use of a clock-timer is marginal at best~ A more appropriate test sequence would be one which represents a typical household water use pattern, allowing the tank to be de-energized prior to the final hot water use during the day. Under idealized conditions, the upper limit of savings achievable with a clock-timer would be to reduce standby losses to zero for the duration of the u'off' time by completely using the last tankful of heated water.
A more realistic limit would be to use the last tankful down to about 100degF which would reduce the temperature differential to about 30 degrees over ambient the off period.
Calvin W. Ek, P.E. and Co Douglas Auburg, PeE., CEM, ELECTRIC WATER HEATER STANDBY LOSSES: COMPARISON OF CONSERVATION STRATEGIES AND THEIR ENERGY SAVINGS, Bonneville Power Administration (un-dated), retrieved 2018/12/25, original source: aceee.org/files/proceedings/1984/data/papers/SS84_Panel5_Paper_06.pdf
You can find a copy of this paper at InspectApedia.com at
inspectapedia.com/plumbing/Water-Heater-Standby-Loss-Elk.pdf
Other interesting facts about standby losses of water heaters:
Gas water heaters have higher standby losses than electric water heaters as additional heat from the water tank is lost through the exhaust flue (an automagic flue damper can reduce that loss)
Larger water heater tanks, because of their larger surface area, tend to have higher standby losses.
Tankless water heaters that do not maintain any reservoir of hot water have zero standby losses.

On 2018-12-25 by EG

I have older model AO Smith electric water heater in this apartment I moved into. Is it better to keep the power turn on or turn it on and off to conserve electricity?

On 2018-08-22 by Tony

My A.O. Smith just started leaking water . serial number 75167-1h17155 model number KGL -40-751. So 1975 water heater.

On 2018-08-01 by (mod) - decoding the AO Smith data tag for manufacturing date

JT that's how I would read it, F = June, 01 = day.

On 2018-08-01 by JT

Looking for the manufacture date of: MF01-0047213-248
If I'm correct in this.. it was made in June of 2001 .. is that correct?

On 2018-07-13 by (mod) -

Ao Smith Water Heater Troubleshooting Ma…

KC I would decode an AO Smith water heater serial number MB00-0070742 as follows:
Factory M

Month B = February

Year 00 = 2000

On 2018-07-13 1 by KC

My AO Smith water heater serial number is MB00-0070742. Would that indicate the heater was manufactured in 2000?

On 2018-07-07 by (mod) -

Yes that's how I'd interpret it, as K = Dec and 05 the year.

On 2018-07-07 by Paula

My hot water heater has serial number K05A143732. Am I correct that the date of manufacture is November of 2005?

..

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Technical Reviewers & References

• Scott C. LeMarr has provided his file of keys to decode Water Heater Age from the data provided on the manufacturer's equipment labels. Mr. LeMarr is a professional home inspector, Certified Professional Inspector/President, MASTER Indoor Environmental Specialist (MIES). Vice President of Wisconsin NACHI. He and his company, Honest Home Inspections, LLC. can be reached at 262-424-5587 or by email to scott@honesthomeinspections.com
• Carson Dunlop, Associates, Toronto, have provided us with (and we recommend)Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment ($69.00 U.S.). Technical Reference Guide, Carson Dunlop Weldon & Associates, Ltd., 120 Carlton St. Suite 407, Toronto, Ontario, M5A 4K2 Canada, ISBN 1-895585-90-2 165pp.
• Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
• John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-873-8534 or by Email: johncranor@verizon.net

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A o smith bth 500a user manual 8 pages jpg ao smith bth 150 specs state water heater hot surface ao smith 50 gallon water heater reviews electric manual a 0 smith water heaters icapish co a o smith water heater cyclone bfc 30 installation manual