Hi, I have an oil burning boiler. Lately there has been a fluid leaking out of the vent pipet?

Hey Bob: I think its just good old condensation. Must be some fluctuations in the outside temperatures. Sometimes when the heat is off warm moist air will travel up the stack and condense on the sides. Then when the sun warms it up or the boiler fires up the frost on the stack will drip down and leave brownish drip marks. Regards, Dale