Instructive Water Heater Failure – Again
Replaced this HWH today for a client, one that I had installed less than four years ago. Same failure – rusted out on top, leaked and put out the pilot light.
This was installed in a tall crawl space; vented through the CMU underpinning and a single wall chimney up the outside wall – not pretty, but what’s killing the HWH?
WTF?
Ahhhhh. I’ll bet this is a “cold” chimney. Exhaust gases go up, hit the single-wall chimney outside the house, and condense moisture out. Acidic water runs back down; drips out of the thimble, and pools on top of the unit. Rusted though the top cover, then the tank itself – jagged hole in the middle right of the tank top is where I (easily) pushed a screwdriver through.
So, I put in a 38 gallon lowboy electric on a new circuit. No problem ever again.
Forrest – fighting the good fight
Edited 8/30/2007 5:22 pm by McDesign
Replies
Well? Anyone else have this happen?
Forrest
Nope.
I got a gas fired water heater in Daytona Beach still going strong.
Installed new in 1971.
I'm just amazed that an inspector didn't red-tag that setup. Flue ending in a corner, under the eaves. Have you checked how badly condensation was accumulating in the attic?
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
The attic is OK - this is the "Attic Recovery" house, so I spent a lot of time up there.
Yeah, that chimney was scary - what was worse, the horizontal part of the chimney in the crawl was between the joists, covered in sheet metal and asbestos sheet.
Nice new electric now - chimney is gone.
When I had replaced the last gas unit ~4 years ago (at midnight!) for the previous owners, they were adamant to just replace it as it was. I did check after a few weeks; no obvious supply or nipple leaks
Forrest - glad to finally make it right
I'm guessing that the flue gasses oft times didn't make it out of the crawl, but spilled back around the heater.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I think you are bang on about condensing flue gas. Even if it isn't the cause it was well thoughtout.
I had a furnace that rotted out due to condensate acid but the vent pipe was also rotted especially at the bends where the condensate collected.
The other possible is that the plumbing leaked on top of the tank from the initial install and ate through. I've worked in a lot of crawl spaces and seen lots of terrible stuff because no one ever goes down there and leaks go unnoticed.
roger
I've seen a fair amount of water heaters that have leaks around the tow nipples that come out the top. Not sure why. I think some installers haven't learned how to install a steel nipple. they under tighten them or don't put enough sealant on them.
Edited 8/31/2007 11:03 am ET by popawheelie