I always check systems BEFORE a camping trip. But if the trailer was sitting for awhile along with the above, check to see if the tube is clear: ie. no spider webs, etc. If all is clear, then there would be another issue. Be sure your battery is good (12V) or you are connected to shore power and are getting 12V. Be sure you did light your stove 1st so you got the propane flowing. It might take a time or tow to get it going, until the propane gets down there. If still nothing happens, you might need professional assistance or assistance from a fellow RVer who has greater experience.