Here is the best “guesstimate”. Generally speaking, a gas water heater should last about a decade (maybe a dozen years if you are lucky). With an electric model you may get a few more years of efficiency (up to maybe 15 years). If it is anything beyond those numbers then your water heater is living on borrowed time!
Let us use an equation, because often times people wonder how long should the hot water continue to flow. For example, if your water heater holds 30 gallons and someone in your home just took a 15-minute shower then you can anticipate that there is about 5 minutes of hot water left. If YOU want to spend 15 minutes in the shower, then you need to wait about 45 minutes.
Nothing about water heaters is an exact science, of course. What is a sure thing in Snohomish, WA is that Shawn Allen should be called if you need your water heater repaired or replaced. That makes it really easy! Snohomish and Seattle area residents have trusted Shawn for their plumbing needs for decades. Give him a call at (425) 367-4744.