I have a 2011 North Country Lakeside 261RLS. The WH seemed fine on propane for the first few days then got a cold shower one morning. When trying to get it to relight on several attempts got a loud bang from the heater but eventually it did relight. Had the unit checked by the dealer who used compressed air to blow it out but did nothing else. This weekend it seemed fine on Fri & Sat. but sometime overnight Sat. the unit apparently when into lockout (after 3 attempts to light) as I once again had cold water on Sun. morning. Several attempts to relight it resulted in a very loud whooshing noise when the propane ignited but the heater did not light after 2 cycles (of 3 attempts each cycle). This morning before heading home from camp tried again and the heater lit normally. Hate to go back to the dealer, big inconvenience and a 70 mile trip, any help appreciated.