Have a Above ground pool that I installed a Hayward 1001 natural gas heater on..has worked fine..
well it started making a strange sound like,,,popcorn popping when running????Took off the top
cover while running and it's not in fan,,it seems to be comming from inside the big metal
sleeve that the input water goes in and then exits the other side ??..works fine,,just makes
that popping,,ratteling sound in that tube,,any ideas?