Have you just moved into a home and you’re wondering how long you can expect your water heater to last? Are you buying a new unit and wondering about the life expectancy of water heaters? Don’t fret, your Boise water heater experts at Dillon Plumbing are here to help. Here’s what you need to know.
Lifespan of Conventional Water Heaters
Most conventional water heaters – those are the water heaters with large tanks full of hot water – last 8-12 years. If they are well cared for and/or you get lucky, yours may last 15+ years or even more. However, the average lifespan of a water heater comes in right around 10 years.

Lifespan of Tankless Water Heaters
When asking, “How long do water heaters last?” it’s important to specify if you’re talking about tankless units. Tankless water heaters should last at least 20 years. Some units will last 30 years or more, especially if you maintain them regularly.
How Old is Your Water Heater?
Not sure how old your water heater is? There’s an easy way to tell on many units. Find the serial number and look at the first three digits. The first, a letter, usually represents the month the heater was made with a letter A-L. “A” is January, “B” is February, etc.
The next two digits are usually numbers and they are the last two digits of the year the water heater was made. “21” would be 2021, etc.
If you see other digits, you may need to contact the heater’s manufacturer or enter them on the maker’s website to see when your heater was made.
When Should You Replace Your Water Heater?
Regardless of the average lifespan of a water heater, you should replace yours when:
- You need to repair your water heater and the cost of doing so is more than half the cost of replacement
- Your water heater is too small for your water heating needs
- Your water heater is leaking and can’t be fixed
- Your water heater has too much sediment to function properly
Get Water Heater Help Today
Whether you’re wondering about the life expectancy of water heaters or it’s time to install a new one in your home, call us at Dillon Plumbing today. We’ll get to you fast and help you find the very best water heater for your home and your needs. We can handle water heater repairs, replacements, installations, and maintenance, so make your appointment today!