Wiffle balls, tennis balls, baseballs and rocks are some of the things I’ve removed from the vent pipes of high efficiency furnaces. Oh yea, I have also removed a few dead birds as well. A blocked exhaust vent will trigger safety devises within the furnace to shut the unit down. The unit will not work until the obstruction is removed, and it is for your protection that the system has this mechanism. Without it, you and your family would be surrounded by carbon monoxide every time the neighborhood kids stuck something in your exhaust pipe! You need to keep that pipe protected! On some older furnaces there is no protection from kids or animals blocking the exhaust pipe of your high efficiency furnace. However, this can be remedied with the installation of a simple screen at the termination of these pipes.
I found two easy remedies for this problem. The first is a plastic 3/4 inch mesh screen, which is designed for this purpose. The second is a piece of hardware cloth cut to size and it is friction fit onto the pipe. But, both methods have their pros and cons. » Read more: What’s Blocking Your Exhaust?
