Rusted AC drain pan

[engineer2]

We had a puddle around the furnace. A-coil drain pan was totally rusted out (everything in Chicago rusts!) A little electrolysis to get most of the rust off, then a fiberglass repair kit to patch it up (sorry no pix of that). Too old and unknown make to find a replacement except maybe for $200-$300. A-coil pans seem to be sold by part number rather than dimensions.

In my case, no need to discharge the system. Used bungee cords to hold up the a-coil and then slipped the pan out. Drilled holes in the plenum to hook the bungee cords. One pan support was rusted out and fabbed a piece of sheet metal for a replacement. Pretty simple repair, but time-consuming.

 

[Milton Shaw]

I had that happen to one of my units. Pan rusted through and leaking. I didn't notice it in the furnace room but down under it in the shop. By the time I could get to it, it had leaked for a couple of weeks. The whole furnace system was 20+ years old so I replaced the furnace and a coil just because I knew the heat exchanger was due for replacement too. Since I had put the original in, I replace it myself. I don't remember the cost, the original was a scratch and dent unit that I installed in 1993 so I figured I had gotten my moneys worth.

 

[starquestMM]

Are A coils not attached to the pan?

 

[bazar01]

Are A coils not attached to the pan?

If he was able to slide the pan out, then it was not attached.

New evap A-coils have triangle sheet metal cover on each side and screwed to the base of plastic drain pans.

 

[hobie1dog]

Just checked ours but it is plastic. Water is dripping from 1/2 way down the slanted coil as if it is running into something there.

 

[engineer2]

Are A coils not attached to the pan?

Yes they are attached, but the whole assembly just sits on the plenum shelf. 4 sheet metal screws plus the triangular sheet metal piece. I was able to open up the plenum to get at the front screws easily. The back 2 required prying it open the plenum a bit, using a 90° impact adapter and doing it by feel. I put the front screws back in, said to hell with the back.

I took the front triangle piece out so I could vacuum the coils easier and shoot some evap cleaner spray in there. They weren't too bad. It's funny, but many YouTube videos claim you have to discharge the system to change the pan. Perhaps on some systems you do.

This is all temporary until we get a new furnace in the fall. So far, no leaks. No idea if the fiberglass will stink if I run the furnace.