I have a high efficiency fuel oil furnace. I have been having problems with condensation in the chimney which is causing water to leak through my ceiling around the chimney. I tried pitting a metal flue liner in but it would not fit because the chimney narrows at one point to the size of a brick. What other options do i have to fix this condensation problem since i can't put a liner down the chimney. Any one have any ideas or things you've done that has worked? My new email address is [email protected]

If you only have a opening the size of a brick in your chimney then you already have a problem to solve. The high eff units need a clear unimpeded air space for the flue gasses to flow. When the chimney as in your case is restricted the furnace will not work properly and this is probably the cause of the condensation. The vapor laden flue gas cannot flow out through the chimney and the liquid in the flue gas falls out of suspension. The company that installed your unit should have discovered this problem. I would call them since they did not check the chimney out properly before the unit was installed.

For any other question about this furnace and the proper venting you need to read the installation instructions or contact the manufacturer to determine what is the best way to vent the appliance especially on high eff oil units.