I have an Aqua-Therm 275 for sale, purchased new in 2001, used 7 months each heating season. Easy to operate & maintain. It developed a leak near feed door this mid February, I haven't operate it since. The stove was drained the same day. An experienced stainless steel welder I got in touch with, via email, said it could be weld shut. I'd rather put the burner up for sale as is right away & proceed in purchasing new burner for next year. I have the sidearm used to heat your domestic water for sale if interestd.
Sale includes: burner, insulated jacket, pressure valves, aqua-stat, pressure/temperature gauge, 2' black stove pipe, expansion tank (may be frozen & leak), Taco circulating pump, draft blower (2 yrs old), all piping but not the al-pex tubing.
Burner has been trouble free during those years, some rust on face of burner from the leak, firebox is rust free & appears to have no other leaks at the time of shut down. Water you see behind the stove was from refilling the stove that day. Feed door & ash door are flat and seals tightly. Cash only please, will write you receipt.
One of the photo is marked where the leak is, bottom right door opening.