: My hot water heater is 7 years old, in the last 4 years I have replaced the control box, gas valve and the hot surface ignition. Now again Im having trouble and have to turn the switch to off and then back on to get it to heat a tank of water. Does it sound like the hot surface ignition again? Or is it just time to get a new one. Also wondering if all these problems are normal or did we get a lemon? Thanks! Dave, I assume you turn the thermostat control knob to get it to heat up. If this is the case the thermostat is defective. 7 years is about the expected life span of a storage gas water heater. Some last up to 15 yrs if you are lucky.