flue gas condensation

ddenny

I replaced an old new yorker boiler that has a tankless coil with a newer efficient system. the new boiler is an oil fired buderus with a reillo gun and a buderus indirect water heater. the house is a 3 bedroom ranch with a full basement I guess about 950 to 1050 square feet not including the unheated basement. maybe it was overkill but I did primary secondary pumping to minimize cooler return water shock. I used an 8148 cold start triple aquastat. trying to make it efficient as I can.
trouble is I'm getting that acid slime runnig down the wall in the basement and a lot of it; I'm guessing due to the low flue temperature going up the chimney. I didn't have an extension ladder to be able to look down the chimney to see if it was lined. I used a stack thermometer to check the temperature and it was only 300 degrees where it comes out of the boiler. I put in an 8124 triple aquastat and set the temperature to 180. also removed those 2 baffles in the boiler and the temp. raised up to 350 in teh flue. I doubt that's enough to stop the condensation. I hate to have to burn more oil just to keep the chimney warm. there was no condensation with the old new yorker boiler because the chimney temp. must have been higher especially since they had a tankless coil.
any suggestions? how would a chimney liner help. I never put one in. it looks like it's just a flexible piece of stainless steel. don't understand how that can keep the flue gases warm enough not to condense. can I still use the 8148 aquastat? is the primary secondary pumping part of the problem? thankyou
dennis

Big Ed_4

Chimney

I guess you have a out side chimney ? North side of home? The liner would heat up faster then a masonary .

300* is too low for a oil fired unit. What size G115 boiler and type of burner

Bob Harper_2

liner

Buderus and the codes say you must reline. Why didn't you get the Logamatic? I love mine. Get the indoor sensor and outdoor reset.

Bob

ddenny

flue gas comdensation

the boiler is the smallest riello you can get. the burner is an f3 riello.
would the logmatic reset control maintain a boiler temp. high enough to prevent flue gas condensation. the 8148 triple aquastat lets the boiler cool down to room temp on a 50 degree day. then when it starts up the flue temp will take a while to heat up. does that mean the 8148 is not really an option for my application? can I put another inexpensive control in conjunction with the 8148. I realy don't want to put the 8124 aquastat in because maintaining 180 temp. defeats the purpose. I wanted to use as little oil as possible.
maybe I'll try the chimney liner first. thank you