A water heater monitoring and notification method includes determining, by a controller of a water heater system, a deviation of a duration of a pre-purge operation from a pre-purge duration average value. The method further includes determining, by the controller of the water heater system, a deviation of a flame current from a flame current average value and determining, by the controller of the water heater system, a deviation of a pulse-width-modulation (PWM) parameter from a PWM parameter average value. The method also includes providing a notification related to a combustion system of the water heater system based on at least the deviation of the duration of the pre-purge operation from the pre-purge duration average value, the deviation of the flame current from the flame current average value, and the deviation of the PWM parameter from the PWM parameter average value.