[Stu from NYC]

Originally Posted by rjm1cc

You might have a way to use a garden hose and force water into the drain pipe. This might clean out the line. On my heater you pour vinegar and or water in a top drain. Do not use this. I have a horizontal pipe that goes into the drain line. It has a place next to the heater where I can use a garden hose. Might start at the outside drain pipe with the garden hose and have some watch the heater to tell you when water starts coming out. When I did it I let the water run on high for about 5 seconds. Let drain out and kept repeating. Then did it from the inside to flush the line. A shop vac can also be used at the outside drain or an air pump.

Thanks for the advise but think it is time to let a professional hvac guy get involved. We do need a pm on the system so that would kill two birds with one stone.

Thanks