FYI Modern Furnace Drains

[Bill George]

The new condensing furnaces have a trap and hose for the condensate water inside. I skipped last year so I just got back from removing said plastic trap and hoses and cleaning. Would not believe the amount of $rap inside! Cleaned all out and reinstalled with some new water back in the trap, just in case. Some furnaces require some water in the drain trap to work correctly.

If that drain line and trap are plugged it will leak and in some cases shut off the heat cycle with a failure LED flashing.

[George Yetka]

Every year on those, I put one in my sisters house and following winter it didnt work because of this. The higher efficiency something goes the more a small thing will stop it from working. ie AR vs AK

[Jack Frederick]

Also, be advised that youy have to be careful where you dispose of the condensate from the combustion process. You can pump or drain the condensate from the AC however you like but. On the condensing furnaces/boilers the condensate is about a 3.2pH. That is pretty hot. I just installed a new condensing water heater on the house and given that I have a septic system I do not want the untreated acidic water in the drains. You can buy small neutralizer kits and the limestone medium. They require about annual replacement of the medium. I did not want to have to do that so I made one out of a couple feet of 4”pvc. I ordered about 40# of limestone. I’ll be installing it the next couple days.

[Bill George]

Also, be advised that youy have to be careful where you dispose of the condensate from the combustion process. You can pump or drain the condensate from the AC however you like but. On the condensing furnaces/boilers the condensate is about a 3.2pH. That is pretty hot. I just installed a new condensing water heater on the house and given that I have a septic system I do not want the untreated acidic water in the drains. You can buy small neutralizer kits and the limestone medium. They require about annual replacement of the medium. I did not want to have to do that so I made one out of a couple feet of 4”pvc. I ordered about 40# of limestone. I’ll be installing it the next couple days.

Correct it will eat out brass and copper lines, PVC or ABS only safe drains. Mine drains into a cast iron floor drain with other water so its well diluted.