[HayZee518]

on the bottom of the heater is a door. lift up and out. there may also be another door of sheet metal inside, take this out too. now you'll hafta get on your knees and with a flashlight look inside. shut off the supply to the heater and wait a few minutes. you'll see the pilot tube and the main gas tube going to the burner. from what you said there is a clicking. this indicates a spark type ignition. at the pilot burner is a triangle shaped flame opening. the pilot light burns pure propane - no air - there is probably a millivolt generator, a copper like tube in the flame path. if this don't work the flame won't stay lit. I worked on a hot water heater that burns propane only this one was in a cellar with no ventilation and no exhaust gas chimney. when the pilot lit the whole four feet around the heater lit up with a whoosh and it burned my eyebrows off. this had a standing pilot flame. check for a spider's nest or a mud wasps nest in the air tube that accompanies the main valve gas tube. clean it out with a vacuum cleaner and use some type of probe - a bent clothes hanger. see what happens.