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.
A Plastic Termination Screen
The plastic termination screen works as advertized, and it’s very easy to install. Some of the setbacks of using this type of screen include:
- Becomes brittle with age
- Must be Glued into place
- Size of holes in screen allow for objects to still be placed in the pipe
- Difficult replacement process
Hardware Cloth
My favorite is the hardware cloth. It can be purchased it ½ mesh and it stops children from sticking objects into your exhaust. There is a major draw back to this method. It needs to be replaced every three to five years. Moisture and the acidic condensation produced by the furnaces exhaust will cause it to rust out. Despite this drawback, this type of screen is low cost and very easy to replace. If you are one of those that take great care of their system, this is a simple check you can add onto your list every season.
Either way the choice is yours, but the important thing to remember is that you must protect your exhaust pipe! If you do, you will avoid unnecessary service calls and high repair costs on your HVAC system!
I love the hardware cloth idea. A practical fix to a serious problem. With the Screen, your comment, “Size of holes in screen allow for objects to still be placed in the pipe” says it all.