Rust on furnace vent

[Norm Peery]

I saw this today on 2 split HVAC units.The air handlers etc., were horizontal, hung in the attic. Rust was noted on both vent pipes and rust in the condensate pan directly under the pipe. Never seen this before, no indication anywhere of moisture intrusion.
Does anyone have an idea?

Norm

[Billy Stephens]

.
Does anyone have an idea?

Norm
.
Heat Exchanger has a hole in it . :eek:
.

[Ted Menelly]

I saw this today on 2 split HVAC units.The air handlers etc., were horizontal, hung in the attic. Rust was noted on both vent pipes and rust in the condensate pan directly under the pipe. Never seen this before, no indication anywhere of moisture intrusion.
Does anyone have an idea?

Norm

Yep. An HVAC contractor has to come for further evaluation for repairs/replacement.

Anyway. That is not just a little rust from the flue. That is a serious fault such as in what Bill might be thinking. I have not seen that kind of rust from a flue pipe in years.

[Michael Thomas]

HE problems seems unlikely in two units, unless a know problem for that model.

Here in Chicago that could be the result of condensation within single wall vent pipe passing through an unconditioned space (the attic) - don't know about your AZ climate, though.

[Norm Peery]

Michael,
The climate is very mild, and very dry. 1st time I have seen this. The weird thing is, it's on the vent pipes for both units. One is rusted worse than the other, but...........
Still wondering.
Thanks,
Norm

[Vern Heiler]

Is there a chance these are Hi-efficiency condensing furnaces that should have been vented with PVC?

[Bob Harper]

The male end of the vent connector is pointing down, which means ALL the condensate remains in the vent and puddles at the base of that ell.

You need a qualified tech to perform a comprehensive inspection and service including combustion analysis to see why this unit is condensing and if there are other problems such as with the HX.

What does the rest of the chimney/ vent look like?

Is that secondary drain on the A coil unplugged?

Bob

[David Bell]

Being that both units are doing the same thing I would Guess that the attic space is too tight and does not provide enough combustion air for the units

[David Bell]

Is that secondary drain on the A coil unplugged?



the secondary should be capped, and a pan switch installed

[john_opwin]

To prevent Furnace filter from rust it should be replaced or cleaned in three or four times in a year.

[John Arnold]

To prevent Furnace filter from rust it should be replaced or cleaned in three or four times in a year.

?? How does the filter get rusty??