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How can I tell the age of a John Wood water heater from the serial number?

Wednesday, April 22, 2020

The first two numbers of the serial number, after a single letter, are the year of manufacture for a John Wood water heater. So, for example, S1112F601242 would mean it was produced in 2011.

To determine the age of another manufacturer/brand of water heater, go to How do I determine the age of my water heater?

Here’s links to a collection of more blog posts about WATER HEATERS:

Are water heaters required to be raised off the floor? 

Can a Temperature and Pressure Relief (TPR or T&P) valve be mounted to discharge horizontally?

Where are gas water heaters not allowed to be installed?  

Is the minimum size water heater inlet pipe 1/2" or 3/4" according to the building code?

Can you use a light switch for a water heater disconnect? 

How can I tell if a water heater is HUD-approved for mobile/manufactured homes?

Can you wire a 240-volt water heater with 120 volts? 

Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater?  

What is the minimum clearance to doors and windows for an outdoor tankless gas water heater? 

What is required clearance for access and working space in front of an electric water heater? 

Why is the water heater older than the house? 

Does a water heater need a shut-off valve? 

Why should a tankless water heater have an isolator/service valve kit installed?

When was a gas water heater first required to be elevated 18 inches above a garage floor?  

Can the temperature and pressure relief (TPR) valve discharge pipe for a mobile/manufactured home water heater terminate under the home? 

What is the purpose of a thermostatic mixing valve above a water heater? 

Does a tankless gas water heater still work with no electricity during a power outage?  

•  Why do water heaters have a sacrificial anode? 

What is the difference between a manufactured/mobile home water heater and a regular water heater? 

Does a tankless water heater require a pressure relief valve?

When is a water heater drain pan required?

Why is there water in my water heater drain pan?

What does it mean when a water heater Temperature/Pressure Relief (TPR) discharge pipe is "trapped"? 

Can I leave a gas water heater in place when remodeling a garage into a family room or bedroom? 

Where do I find the water heater in a mobile home?

Does a tankless water heater in an attic require a drain pan? 

Does an electric water heater require a disconnect? 

   Visit our WATER HEATERS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

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