For minor issues on a newer system, like burner failure or circuit breaker issues, it may be the most cost-effective option to simply schedule a water heater repair. As systems age, however, repairs may only be so cost-effective in the long run. Older water heaters may develop leaks, rust, and other problems. Repairing it will only provide temporary relief before another component breaks, and at that point, you might want to consider replacement. Replacement is also necessary in the case of some emergencies, like water tank leaks!