If you have a pool heater that is getting hot on the outside to the touch, or the flames are larger than you remember, it is time for a cleaning. Over time insects can make nests and add flammable materials like dry grass and twigs to your heater on the inside. You can also have wear on parts that are meant to keep the flame contained. If you notice anything out of the ordinary call for service. If you have a major issue, turn off the gas to the heater as well while you wait for service!