What happens is quite simple. Most, but not all, high-efficiency furnaces are vented through a side wall using PVC 636 venting. Usually, there are 2 pipes. Occasionally you will see a concentric vent, however not very often in Saskatchewan because they don’t work well in our extremely cold winters. So, if like most of us, your home has 2 pipes exiting, one is the vent and the other is an air intake. The air intake pulls in air to feed the fire in your furnace, the other pipe expels the products of combustion.

When the furnace vent or air intake is blocked or partially blocked by snow, safety switches in the furnace sense this and automatically turn off the furnace, so that the gases aren’t trapped in your home.

How Do You Fix it?

The quick fix is to go outside to the vent and simply remove the blockage. Here in Saskatchewan, the majority of instances occur because of ice or frost. Occasionally it will be snow, especially if we have a bad blizzard like the most recent one we experienced in 2007 in Saskatoon when snow blocked many homes vents. Not sure it was quite as bad as the one in St. John’s though!

After you remove the blockage from the vent, most furnaces will simply restart on their own, however, some furnaces require you to shut the furnace off at the power switch or breaker, count to ten, then turn the power back on. This is simply rebooting the computer inside the furnace. So, if you find your furnace is ever blocked by snow and you have to remove the blockage, follow those instructions to see if you can get it going again. If your furnace still doesn’t fire up then it’s time to call JOB Heating and Air Conditioning. We offer furnace service and we offer emergency after-hours call-outs 24/7.

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