evap core corrosion

[John Dirks Jr]

This unit is 14 years old. It was functioning in the heat mode of the heat pump.

When you see corrosion like this, do you write it up for that alone, even if the unit is functioning?

I did write this one up for the corrosion plus a very dirty blower cage.

Is rust like this a sign of eventual failure or is it common to see this?

[Dom D'Agostino]

It's very common in our parts, especially with a 14 year old coil. I would have expected to see more rust, based on age. Is that a Rheem or Ruud AHU/furnace?

Dom.

[John Dirks Jr]

It's a Ruud.

[Scott Patterson]

I would simply say; even though the unit was working during the inspection, it was at the end of it's expected life and that any future operation is just good fortune. I doubt I would say anything about the oxidation on the copper. I might include a picture if I had a good one.

This is pretty much my standard statement whenever I find any HVAC unit that is over 10 years of age, in my area.

[Phillip Stojanik]

The corrosion is very typical especially for a 14 year old evaporator coil. A final failure of the coil will likely be the result of refrigerant leaks that will eventually form at the copper tubing penetrations through the rusty metal plates.

The rusty metal around the tubing penetrations will become distorted as the corrosion gets heavier and will eventually press and indent into the softer copper tubing. If you see this kind of corrosion along with an oily looking circle around the tubing penetration then the leaking has already begun and its time for a new evaporator coil.