During an El Cajon summer, most people don't think much about hot water. Then the first cold morning comes, everyone in the house wants a hot shower, and a water heater that's been struggling since spring can finally give out. Heaters tend to fail when they're working hardest, and here that usually happens when the weather turns cold.
It's better to call before the cold weather, while things are calm. A pilot that needs relighting more than once is a sign of a problem. So is water that's hot but not like it used to be, a tank that runs out with showers left to go, or rust and moisture at the base. Call at that stage and there's time to weigh a repair against the tank's age, size a replacement to the family living there now and have the contractor check the venting and earthquake straps.
Describe what the heater's doing, and what it means gets explained in plain English. If it's a small fix, you'll hear that. The decision is yours.