Chimney Problems.....

Bill_77

I have a customer whose oil boiler (Weil McLain WTGO-7 7” vent) was having drafting problems. After checking the boiler it was determined to be the chimney. He called a chimney sweep and found the chimney (8” x 13”) had been lined with four inch standard smoke pipe surrounded with cement. The house underwent construction two years ago with over 7 feet added to the top of the chimney. The building contractor (the guy involved with extending the chimney) thinks his guys found the smoke pipe in the bottom half and continued the smoke pipe up to the top. Until yesterday the boiler seemed to be drafting but I have no proof as to previous tests showing the draft. A four inch wire brushing was able to remove a portion of rusted smoke pipe and re-open the chimney. This is my problem… (Other than a 4” chimney) The chimney is located in the center of the house completely surrounded by finished walls. The sweep says he cannot remove the pipe and cement without major damage to the interior. I have no place on the outside walls to place a side wall power vent. I do not feel safe with running the boiler with a 4” chimney. I though if it would fit a 4” liner with a chimney top power vent. I and stumped and would love to hear a few Ideas.



Thanks

Jim Davis_7

The rusted out smoke pipe is an indication of poor venting. Lucky this didn't soot up the whole house. The boiler would have to be grossly underfired to work at all in a 4" chimney. You are correct in saying to use a power vent chimney cap. Should have no problem venting as long as it is sized properly. Not sure what brand of chimney cap ventor to use? Exhausto? Field?

Ken_40

There are so many ancillary

issues involved here....

Get a pointed masonary bit/mandrel and hope for the best, e.g., drill to 7", hoping not to wreck the entire chimney completely (the self-centering aspect of a blunt point bit being a plus and with luck will not rip up the existing flue liner, and get rid of the cementatious surround - and, he 4" single wall and run a s.s. liner inside. With the interior location and tall stack, a 6" may fall into an acceptable diameter reduction based on AGA venting code/specs.

I cannot imagine adequate draft or venting intergity with half single-wall in some areas, and cemenatious remains in another. Esepecially on a warmer day when draft will be minimal and spillage a major danger!

Where does one get a carbide 7" pointed masonary drill and extensions? I have no idea. It's just a thought that comes to mind. Using a draft inducer may work well too. Then again, a draft inducer and a sid wall vent may be the only option?

KAG

Chimney venting

I believe you can have chimney relined once the obstruction is removed either with a all fuel vent kit or a cement liner. I seen it done on this old house where they stuck in a rubber tube and filled it with air then poured cement around.