No hot water is a common problems on aging water heaters in the San Diego area. It is usually caused by a bad thermocouple, which we recommend you call us to fix. But in the mean time, to get hot water again, you need to re-light the pilot light. There are instructions on the water heater how to do this, but it generally involves the following: 1. Turn the black knob on top of the silver box (gas control valve near the bottom of the water heater) to pilot. Press the button down with your thumb. If there is a igniter button on the gas control valve (typically seen on water heaters newer than 2003) press this button every 5 seconds for 30 seconds, while holding down on the black button on top of the gas control valve. After 30 seconds, release your thumb and turn the black knob to the ‘On’ position. If there is no ‘igniter button’ you have an older style water heater. Hold down the black button, and with a lighted match, put the match into the combustion chamber (the open area at the bottom of the water heater, where there is a round burner). Hold the match with a pair of needle nose pliers, near where the 3 tubes meet at the round disc. The pilot gas should ignite a small flame. Continue holding down the black knob for 30 seconds, and then turn to ‘On’…….Still dont have hot water. Give us a call. We will be out in a jiffy!