Most water heaters have a label with the date of manufacture. If not, you can usually decode the year from the serial number, check out this handy guide to see how.
If your water heater is more than 8 years old, you should definitely replace it soon. Gas heaters last about 10-12 years, less if you don't do regular maintenace. When they fail, it's often sudden, sometimes catastrophic. Flood damage costs an average of $3,300 to repair (nationwide; probably much more in Burlingame). Scheduling a replacement is a lot less stress than having to do it after your water heater fails. It can take a week or more to schedule a heat pump replacement, so if you have an emergency, you may be stuck with a new polluting gas heater for another decade.
And of course, there are the emissions. Every year, your gas heater belches out about 3,880 pounds of CO2. Coupled with all the methane leaks and unburned gas, that adds up to the equivalent of 6,200 pounds of CO2, no matter how old your water heater is. Since you'll be saving money by going electric anyhow, why not do it now, and avoid the hassle of an emergency failure, and the ongoing pollution of your current water heater?
So, if you care about global warming, it's worth looking into a replacement even if your water heater is only about 6 years old, and if it's over 8, it's definitely worth getting a quote for a replacement, even if just for the economics and the peace of mind.
If you are not ready to replace yet, you can send yourself a reminder to look into it later, before it's in danger of leaking.
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Back to the Burlingame Guide to Climate-Friendly Water Heating.