The submitter wrote: "Smell a Rat? It’s a good idea to cover all unused knock-outs."

The submitter wrote: "Why mess with all that high-tech gadgetry in a humidifier? A Cool Whip container filled with water will do the same thing."

Recycle: Inexpensive plug for the cleanout.

Rain gutter capped on both ends? Shouldn’t you have at least one downspout??

Why cut a hole in the roof and why not place it near the window AC?

The submitter wrote: "FOILED! Cheaper than buying another section. This section of water heater flue pipe is made entirely out of aluminum foil."