I have a 6 month old Sears (AO Smith) 50 Gal gas water heater. While in my basement the other day, I noticed the plastic red " HOT" and blue "COLD" rings around the heat trap nipples were melted around the area where the exhaust flue pipe is. So I raised the T-stat to fire up the water heater to test, but found no excessive heat around the exhaust and draft hood. Testing with a match confirmed the draft was good. By the way, the exhaust pipe is 3" rigid duct. The specs to the water heater allows 3" or 4" ducting. I took apart the duct to check for blockage, and it looked clear. Now last night I was in my basement again, and this time I noticed excessive heat around the draft hood, So much that I could not keep my hand there for that long. When I did the draft test with a match, the flame was blown out. I turned off the water heater and tested again with the match, and the flame was still blown out. I also tested it with my furnace vent without the furnace running, and that was blown out too. The only thing I can think of is that it was very humid outside last night and the air was still, possibly causing no updraft. I rechecked about an hour later, and the draft was good. What could cause this?
- posted
12 years ago