Furnace Ideas / Help

67Dart273 said

No you are thinking of AC. This is the drain from the condensing furnace and has to be trapped "normally" to keep combustion gas out of the drain, and out of the heated space

He was going to punch the drain out through the wall

Here is the manual

https://runtruhvac.com/wp-content/uploads/2019/12/88-A951X001-1C-EN_10222019-1.pdf

Click to expand...

Yep, you're right I am. The white assembly appears to have an integral trap, bottom should be barbed for fitting tubing. IOM is not clear on this but sort of hints around its function. See below reference from page 62 (note this is not the application in question, just showing an explicit reference to the white component as a trap.