At this time of year, the cries for help come regularly and often. The actual problem might differ, but the root cause is often the same: a dirty furnace filter. There's no other way to say it: a dirty heating system filter can spawn a myriad of problems, from minor to catastrophic and from relatively inexpensive to costly.

See if any of these cries for help sound familiar:

The cry for help: The air in my house smells musty and dirty. I notice it the most when I walk in the door at the end of the day.

Our response: It sounds as though your filter is clogged with the dust, dirt, pet dander and other airborne particles that it's designed to trap, before it winds up on the furnace motor. With nowhere else to go, all of those contaminants are now spewing through your registers. No doubt: it's time to replace your air filter.

The cry for help: I swear that I don't feel warm air coming from heat registers even though I hear my furnace turning on and off.

Our response: Consider yourself lucky. Your furnace is still operating, but it's probably having a difficult time channeling heat. It's probably time to replace your air filter. A clean filter will help your furnace run smoothly and reliably – and will help keep you warm.

The cry for help: My heating system won't turn on, no matter how high I set the temperature! I am completely freaked out that I might need a new furnace!

Our response: Try not to panic; we'll be right there. Check the filter in the meantime. It could be so utterly dirty that it caused the furnace to break down. More than half the time, a clean, new filter is all it takes to revive a furnace.

The cry for help: I feel like I need to reach for a bottle of aspirin before I open my winter utility bills; I can't seem to get them under control. My family and I don't like being cold, but we do turn down the thermostat overnight and during the day. What else can we do?

Our response: Check your air filter by holding it up against a bright light every month – say, right after you pay the utility bill. You'll be glad you did, even if you have to change the filter only once every several months. Changing the filter is positively the simplest, most proactive step you can take to ensure that you derive peak efficiency from your furnace.

The cry for help: My neighbor is complaining that he has to replace his 18-year-old furnace, and I told him that he's lucky it's lasted this long. He really shouldn't be crying on my porch, right?

Our response: A new heating system is a big expense that catches many homeowners off-guard, so that could be why your neighbor is feeling stressed out. But it's true: his older furnace went the distance, probably because he took good care of it through annual maintenance checks and (you guessed it) regularly checking and replacing the filter. His new Energy Star furnace should last even longer. And hopefully it won't be long before he comes to see that big expense as a good investment because it should cost him less money every month to heat his home.

The cry for help: Please don't tell my wife I'm calling you, but I need some advice about how to change my furnace filter.

Our response: Your secret will be safe with us: Turn off your furnace; locate the filter in the blower compartment; remove the old one, paying attention to the direction of the arrows on top of the cardboard frame as you do so; place the dirty filter in a plastic bag; and slide the new filter into place, being careful not to crush or jam it in place. Do it once and you'll feel like a pro.
 

Even we're amazed sometimes that such a simple, mesh contraption like a furnace filter can provide such an important function – and wreak such havoc on your heating system and home when it gets dirty. And that's a dirty truth Experts In Your Home are determined that you live without.

Do you know what to do if your heating system breaks? Find out the questions to ask in the free eBook below!