How Old Is My Ruud Water Heater? 6 Styles Of Serial Number!

How old is my Ruud water heater? You can tell the age of your Ruud water heater unit by decoding its serial number found on their labels. There are six styles of serial numbers that differ per model of the Ruud water heater. So it is best to know the model first before determining the age of your water heater.

Have you recently purchased a new or used Ruud water heater? Knowing the unit’s age is proven to help you determine whether the appliance will last long or not, especially if it is second-hand bought from a thrift store. Well, I was in the same situation as you are, but after a series of scrolling through the web and researching for a way to know the age, I have found the easiest way to do it. Do you want to share the secret? Then, get your place and read until the end of this article.

How old is my Ruud water heater


Ruud Water Heater

Did you know that the first one that invented the water heater that we enjoy today was the primary owner of the Ruud Company that still exists today? For more than a century from today, Edwin Ruud invented the hot and cold water heater, which we enjoy until today. Since then, RUUD has been one of the leading manufacturers of cooling and heating products in the whole state of America. 


Styles Of Serial Number

Since the company is already building for over a century ago, it is understandable that they’ll have different formats of serial number assignments, which is a little confusing for those who do not know. So how will you be able to know which Ruud water heater serial number is the correct one as your reference in telling the age of the water heater? Here are the different styles of serial assignment in the RUUD water heater.


#1. MMYY/plant line code/consecutive serial number

The first style has the order of Month, Year, and plant line code. The first two numbers correspond to the number order of the month, while the 3rd and 4th numbers correspond to the end year. After the four digits, you will see a letter corresponding to the plant line code.


#2. MM/YY/consecutive serial number

The second style that we have is similar to the first style on our list. The first two numbers correspond to the number order of the month, while the 3rd and 4th numbers correspond to the end year. The difference is that the second style doesn’t have the Plant line code, unlike the first style. However, a serial number with a prefix of RHLN on the tag has a manufacturing date printed on the label as MFG.


#3. Plant/WW/YY/consecutive serial number

The third style that we have is different from styles 1 and 2. The third style begins with a plant code, followed by the week number, then the year. You can refer to the plant code on Ruud Water Heater Age. Instead of the month, the week number of the year is used at the first two digits of the serial number, while the third and fourth determines the end year number.


#4. Plant line code/MM/YY/factory coding

The fourth one on our list consists of a plant line code followed by the month, year, and factory coding. The manufacturer’s serial number is different from the unit’s serial number so you might get confused between the two. The manufacturer’s serial number consists of numbers only, whereas Units serial number has letters imbued with the numbers.


#5. MM/YY/ID/sequence number

You might find this format similar to the first style, but the letters after the four numbers upfront are for the ID code. However, you can still determine the manufacturing date by the first four numbers, which have two digits for the month and the other 2 for the year.


#6. YY * MM-sequence number

The last style we have is a simplified serial number format. A dot separates the month and the year. At the same time, a dash is located between the month and the sequence number of the product. Among all the styles on this list, style number 6 is the easiest to decode. You only have to know that the first two-digit is the year then the month, which is highly noticeable compared to the other styles.



So, how old is my Ruud water heater? The formula is simple. You’ll have to find the serial numbers first, then identify which styles suit them. You can use the techniques mentioned above listed above. Determine the month and year or the week number and year. Then deduct them to the year we are in currently. That way, you’ll know how old your Ruud water heater unit is. Click on these links to read related articles; know what to do if tankless water heater is frozen

Let’s say that we have a Ruud water heater with serial number 0585A35604. Then let’s take a good look at the format. The sample serial number is similar to styles 1 and 5. Nevertheless, they have the same month and year format. We can say that 05 stands for May and 85 is for 1985. Today is March 2020, then deducting 1985 to 2000, you can conclude that the age of the water heater is already 25 years old. If you have a different water heater brand, you might want to check out How Do I Determine the Age of My Water Heater as a reference.


It’s A Wrap!

No more thoughts on “How old is my Ruud water heater” since you already know the technique in reading the serial number for the Ruud water heater unit. You might as well know that your water heater is good to use for a long time, or you should replace it with a newer unit. Don’t hesitate to know these things too; read about how much energy does a water heater use and how much does a water heater blanket save.

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