Found a small leak on the back side of my OWB. The heat from my firebox comes towards the front door and then up and back through 11 tubes to exit up the chimney out the top back of the burner. Well no matter how dry your wood (All of mine is well seasoned) when the draft fan kicks off the exiting gases start to cool going up the chimney. This in turn will put moister on the bottom back plate on and off. the weld all along the back is in bad shape. Purchased this new at an auction 5 years ago. It was built by a Mom and Pop shop over in Whitespider country. Called the company and they have already had 2 of these back in the shop to rework and they told me to bring it up and they would make it right. (With some cost to me) So got it all unhooked today, will load it on the trailer tomorrow and head out. Guess it did not do me a lot of good to run distilled soft water with the PH check often worrying about corrosion from the inside. Finally burning LP for heat the first time in 5 years and not liking it at all!!