Sometime we take for granted the comfort in our own home. We go day by day, forgetting its a mechanical piece of equipment heating and cooling our home. That piece of equipment, needs to be maintained just like our vehicles. Let's take a second, in this very cold month of February to check a few things, that will help maintain our furnaces. Lets start with filters. Its important to always have a new clean filter, not only for our health, but the health of our furnace as well. If we let our filters get plugged, our furnace will get starved for air, and it will suck all that dirt into the furnace.The Furnace then works harder to maintain our home. If our furnace is working harder (especially older furnaces) things will start to go. Would you run a 20 year old car with dirty oil? Our filter choice is also very important. I always suggest to buy very cheap filters and change them monthly. The more filtration we install before our furnace, sometimes backfires on us for the life of our furnace. We do not want to starve it of air, that's extremely hard on the furnace.
Finally, for gas furnaces, it's important to make sure our chimney vents are clean. We want to look to see if there is Ice around the chimney, and debris around the fresh air pipe. Just this week we went to a home with a gas furnace giving the owner problems. It had a concentric chimney (means both pipes come out of the home in one hole.) Once we pulled off the hood, we see Ice, debris, spiderwebs, and ladybugs in the outer vent. This vent is the "combustion Air" for the furnace, and it was blocked off so the furnace thought there was a problem with the venting, so it wouldn't fire. Once cleaned the furnace fired back up.
If you have an older furnace, don't ignore it until it breaks Sunday night at midnight on Christmas. Gary always says, "dont let your furnace tell you when to change it, you chance it when its best for you" Keep and eye on it, keep it clean, and recognize when it starts acting up. Don't wait for it to fail.
P.S Any Home with a gas furnace should have Carbon monoxide Detectors. You can buy a plug in to outlet one for fairly cheap at home depot or home hardware. It cheap insurance for your family.