Rheem water heater (C) Daniel Friedman Water Heater Age & Manuals Q&A
FAQs on Water Heater, Geyser, Cylinder, Calorifier Age or Manuals

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FAQs on water heater age decoders & water heater manual sources:

Here are answers to frequently-asked questions about figuring out the age of your water heating appliance.

This article series explains how to determine the age of a water heater, we provide a chart that decodes the year of manufacture of water heaters, and we discuss the conditions, maintenance, and factors that affect how long a water heater can be expected to last.

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

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How to Determine the Age of a Water Heater

Rheem water heater (C) Daniel Friedman

Questions about how to find the age of a water heater, geyser, calorifier, cylinder or other water heating appliance, posted originally at WATER HEATER AGE & MANUALS - topic home,

On 2017-05-04 by (mod) Ruud electric hot water age information

Dorothy you'll need to find the serial number as that's where the age is encoded.

On 2017-05-04 by Dorothy

Looking for the age of my Ruud electric hot water heater midel # PE 40-2

On 2017-02-04 by Barbie

Looking for age of HHG30XMIGO Serial # 65319 MM Hedges Mgf. Co. Inc. 30 Gal. gas water heater.

On 2017-01-13 by (mod) - where to find age of a furnace


This article series decodes the age of water heaters for domestic hot water: geysers, cylinders, calorifiers, or "water heaters" while you are asking about the age of a forced air heating system for heating the interior space of a building.

Using the search box just above to look for "FURNACE AGE" finds

AGE of HEATERS, BOILERS, FURNACES that's a good place to start decoding the serial number of your furnace to find its age.

On 2017-01-13 by LG

How do I determine the age of my Rudd gas forced air furnace?

On 2017-01-11 by (mod) re: age of a Nordyne water heater

Perhaps as old as 1952.

A leak at the water heater top can be repaired * IF * the threaded tapping into the tank is not badly corroded. Else it's probably new heater time. YOu can use the page top or bottom CONTACT link to send me some sharp photos for comment - that may help. Also send a photo of the whole heater and of its data tags

On 2017-01-11 by Bonnie

I have a leak from the hot water exit pipe around the connection on top of the tank. Can this be replaced or will I have to get a new tank? It is very rusty in the area. How old is this gas water heater..
mfg. Nordyne
SERIAL # TM 0193004952
Thank you

On 2016-12-27 by (mod) re: age of a Fowler electric water heater

I Speculate from the serial numnber 1989 - and will research further.

On 2016-12-27 by James McKenzie

Craftsman home built in 1930 has Fowler Porcelined Electric water heater, Model AFT-50, ser# OX2989. This unit has been in service a long time, and a fair bit larger than contemporary 50 gallon models. I'd like to know just how old it is.

On 2016-10-04 by Stan - John Wood water heater age

Age of water heater?
My heater is a John Wood.
The serial# is 1946A010890.
I know the tank is less than 15 years old but exactly how old?

On 2016-09-16 by jeff

This heater started leaking a few days ago. Was it made in 1980..?

On 2016-09-12 by (mod) re: fixing corroded Intertherm water heater plumbing leaks at a connection


If the threads into the tank itself are intact you should be able to replace just the connector.

On 2016-09-12 by Richard

I've got an Intertherm 40 gal. electric, glass lined, hot water heater that's 23 years old.

A plastic nut connection at the tank intake failed. Wondering if I should get a new tank or just replace the plastic connection pipe? Anyone with Intertherm experience?

On 2016-09-11 by Anonymous

How old is my hot water heater, It's model No. Is MIRE50S5DS12

On 2016-07-16 by (mod) age of Hotpoint electric water heaters

Judy for Hotpoint electric water heaters, the age is encoded in the heater's serial number, not the model nor catalogue number.

Take a look at the data tag on your heater.

If it is in the form RN0603123456 then the age is encoded in positions 3-4-5-6 starting from the left - so my example would be M M Y Y or 06 03 or the 6th month of 2003.

Some GE and Rheem heaters also use this encoding pattern.

As your heater is an old one it may use a different scheme. Use the page bottom or top CONTACT link to send me sharp photos of the data tag and of the whole heater and I can look at it further.

On 2016-07-16 by Judy

We have a Hotpoint Electric Water Heater Cataloque number 100WBSC521035. It was here when we bought the house 25 years ago. It says 50 gallons on it but it is the size and shape of the washer and dryer which sit on either side of it. I am worried that it will cease to work sometime and I don't have a clue where to look for a similar new one.

On 2016-07-01 by (mod) re: water heater tank liner affects heater life

Alan, Certainly the quality of liner of a water heater is an important factor in heater life; other factors include volume of water usage, water chemistry, and water temperature, installation details, and maintenance.

On 2016-07-01 by Alan Evans

Bought a house with 33 year old State water heater. I have been told State made a ceramic lined water heater, can this be why my 33 year old heater is still working fine? Model CV40NRT4
Serial # F86149261

On 2016-06-05 by (mod) re: age of a Hoytt automatic water heater

David I didn't find Hoyt automatic water heaters in the Carson Dunlop Technical Reference Guide so we constructed a separate page to help you do this - found by searching InspectApedia for HOYT WATER HEATER AGE - please see

I'll add your heater information there in case that helps others;

Yes please use our page bottom or top CONTACT link to send me some sharp photos of your water heater and all of its data tags.


On 2016-06-05 by David Stackhouse

Trying to find out age and value of Hoyt automatic water heater; size 3 serial number 16372 patent July 15th 1919.Feel free to contact me at for pictures if necessary

On 2016-03-26 by (mod)

Don: above you've found an article on water heater age. Search for AIR CONDITIONER AGE for help on A/C units. There you'll read about de-coding dates in the serial number depending on the A/C brand.

On 2016-03-26 by Don

trying to verify age of the AC unit

On 2016-02-26 by Wayne Money

Lochinvar water heater with serial number 1442A030332. Can't figure age. Help?

On 2015-11-20 by Anthony

How Old is My Kenmore Hot Water Heater Power Miser 9

On 2015-10-23 by (mod) re: age of Norge water heaters

I can see why you ask, Mike, I'm having a heck of a time finding out who manufactures the Norge water heater, finding a Norge water heater manual, or other information. I did find this telephone number for finding a Norge water heater rep in your area: (800)447-8371.

In Norway one finds - Høiax is a long-established manufacturer of water heaters (since 1927) and an international marketer of stainless steel water heaters.

Høiax AS, Trippeveien 5, 1618 Fredrikstad, Norway | Tel +47 69 35 55 00 | - See more at:

On 2015-10-23 by Mike

I have a Norge electric water heater, model 60-52 D, S/N: 0347-3500 P. Any idea how old it might be?

On 2015-06-15 by (mod) re: age of Giant Cascade water heaters in Canada

Giant Cascade water heaters are distributed in Canada except in the West and are more easily found when the "Giant" brand is appended to the name. ( ) As a look at the product manual didn't show a break down of the data tag numbers you'll want to contact the company directly at
or by telephone at 1-800-363-9354

On 2015-06-15 by (mod)


:eter (no email)

COMMENT:I have a Canadian made Cascade 40, model 6E2175SC, sn#0011 186038, cat# A4921

What is the age of this unit?

Question: what about water cylinder tank warranties?

(Oct 11, 2011) sharon said:

need to know about tank warranty


Sharon see

The warranty period and terms of your specific water tank depend on its model, age, and of course proper installation. Typically you can find that information in the installation manual and papers for your unit, or if you don't have that information, you'd contact your heater's manufacturer and give them the model and serial number of your water heater.


(Feb 11, 2013) B Skiba said:

We are worried about our hydronic water heater. Our neighbors had severe water damage when their water heater had a major leak while cold water kept flowing into the heater. Their system is similar to ours. We are going on vacation and wonder if we can turn off the cold water intake so that if the water tank develops a leak, at least we won't have a flood. Can we do this safely?


(Feb 26, 2012) Karen said: I want to know the year of my hot water heater

(Nov 5, 2012) Alexandra said: I am trying to find the age of my Hi Test Hoyt water heater. The serial is A87RNH1373190, model A40HM

(Dec 30, 2012) donna said: trying to find how old water heater is model# 71-40db seaial# rh0900b06241

(Feb 5, 2013) wells said: 64 gal model EXR90-52

(Mar 1, 2013) Lee Harding said: I'm trying to determine the age of my GSW hot water heater.Model 6G505DE1
Serial # 50704 535391. I can't tell from these numbers.

(Mar 21, 2013) beckett said: how do i tell the age of my hot water tank


You can often find the year and month encoded in the product serial number, as we describe in the article above.

Question: decoding the age of an Envirotemp water heater

(Mar 29, 2013) Anonymous said:

how old is an Envi-ro-temp water heater model#mhe2e30hs035v serial # 9812126163 product# 0820183 Thank you, Cheryl Satterwhite



If we assume that your Envi-ro-temp water heater is an Envirotron product I can give this information from CDA's technical reference cited in our References section:

Envirotron went out of business around 1980 - which would your heater at least 33 years old. The current incarnation of the Envirotron name is a company that provides "green technology education and resources" and has their own website with that name.

There is also Solatherm-Envirotron, 1983
Solar Hot Water System for a Newspaper Building: Final Report
Solatherm Envirotron, 1981 [book about 151 pages)
This company published a number of solar water heater studies and documents.

Is your heater a solar unit?

In any event, from the serial number serial # 9812126163 I would bet your heater was made in year 98, month 12, or December 1998.



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