water in furnace

drhvac

customer had no heat on a very cold snowy night here in the northeast the other day, but it started working erratically, and was working when I got there the following morning. I checked and cleaned all the drain hoses and trap. I checked the gas pressure, pressure switch pressures, and did a combustion test on it, everything was fine. The combustion inlet pipe is kind of low to the ground and I think a snow drift might have temporarily blocked it causing the erratic heat operation. Inside the furnace it was wet, not on the bottom where the blower is, but up in the burner compartment in the front of the heat exchanger where the drain hoses come out of the secondary heat exchanger. Nothing was obviously leaking, no stains of water or anything, but the tray was wet and it was rusted like it has been wet before. Any ideas? Can't be the secondary heat exchanger or I would probably see water on the bottom? This is a Ruud 90% about 10 years old.

Thanks

Harvey Ramer

Is the

furnace sitting in a cold environment? Could be condensing every time it turns on. Also check your return air temp and make sure nothing funny is going on there.



Harvey  

drhvac

furnace

is in a basement

Ironman

Flue Inlet

Does the intake pipe pass through an unseated area? Could be condensation. Are pipes terminated properly? Could also be flue gas reversion.

drhvac

the piping

It's in the basement, so it's not in a cold area. Also the combustion intake is on the top right side of the furnace where the leak is on the bottom left, so it's not close.