No Gas in Heating Element

If you are using the heater at temperatures below 40 degrees, ther will not be enough gas vapor to run the heater. If the temperature is above 40, look for an obstruction in the gas piping or gas valve itself. There is a small screen on the inlet side of the gas valve that you can inspect if you remove the inlet hose. Make sure you reinstall the hose using a teflon base pipe sealant on the threads.