The pilot light on my hot water heater keeps going out. This is a common problem especially with some of the first generation FVIR (flammable vapor ignition resistant) models. These water heaters have built in safety devices designed to shut the gas down if the temperature in the combustion chamber gets to high. Several things other than the intended flammable vapor incident can cause this to happen. The most common is a dirty air intake screen unfortunately some of the early models can’t be cleaned and the only remedy is to replace the unit. Another common problem is the heater being located in the attic. In July and August we get a lot of calls to relight water heaters because the air in the attic is so hot that it causes the temperature in the combustion chamber to get to high thus causing the safety device to shut the heater down. Unfortunately in most cases the only answer is to replace these problem hot water heaters with either newer better designed tank type gas water heaters or if feasible a tankless water heater.