Hi all,
I am considering a HI-Efficiency gas boiler replacement for my 50 year old cast iron oil boiler. They only drawback I see is that the direct vent has to go to side of the house (un-paved shared laneway) and it will not look very nice. Two black PVC pipes sticking out from the foundation and running about 3 feet high. The drawbacks I see are
1. Unsightly
2. Moisture problems with the brick veneer
3. Can be easily plugged by animals or by mischief
4. Coring the limestone foundation may cause cracks.

Is there any reason why Hi-Efficiency boilers can not use natural vent (i.e. Chimney) with an appropriate liner? Is the a problem with condensation in the flue gas (100 °F)

If a still want to use my chimney with an appropriate liner what other hi-efficiency gas boilers >= 88 % (AFUE) are available?

I want to consider all my options because I see this as a long term investment.

thanks in advance
John K