How to Get Rid of That Musty Smell

Imagine this: You’re a kid, and your family’s been on the road all day. You and your siblings are jammed into the backseat of the car, arguing over whether the windows should be up or down and who gets to control the radio. Finally, after a bazillion miles and way too many hours, you pull up to your grandma’s house. You pile out of the car and race to the front porch. Grandma opens the screen door wide, and you rush past her into the kitchen. You take a deep breath, and it smells just like you remember: Old mixed with musty mixed with whatever’s going in the crockpot.

That musty odor can be a bit nostalgic at Grandma’s house—but not when our own house smells that way. Then the frantic search begins: Where is that smell coming from and how do I get rid of it?

A Dirty Denver HVAC System is the Most Common Cause of Musty Odors

Admittedly, musty is a bit of a subjective description. It’s not quite “rotten,” and not exactly “mildew.” It’s more like, well… old. And it’s a bit tricky to track down. First, try these tips:

• Vacuum your upholstered furniture. 
• Clean everything else while you’re at it: your walls, under your sinks, every square inch of carpeting (including underneath the furniture you haven’t moved for 14 years), every blade of every ceiling fan… everything. 
• Scope out the basement for leaks.
• Check the dark corners of your pantry for a potato that’s past its prime. (Not kidding. Many a mystery smell can be traced to a rotten Russet.)
• Clean underneath your teenager’s bed. You just never know what’s living under there.
• Make sure there’s plenty of air circulation throughout your home.
• Open your blinds and curtains. Sunlight is a natural disinfectant!

If none of those things eliminates your musty odor, chances are good your HVAC system is to blame.

What’s in Your Ducts?

We’ve helped hundreds of Denver HVAC customers track down musty smells. Typically, we find one or more of the following problems.

Clogged air filters can cause musty odors. 

Your furnace filter doesn’t just prevent dust and dog hair from moving through your ducts. It also traps mold and mildew. If you don’t regularly change your filters, those stinky microbes flourish. Plus, if the filter is clogged, air can’t move through it—which means all the dust it should be catching settles into your duct work. You can try vacuuming your filter to bring it back to life, but if it’s really packed with grime, it’s best to replace it.

Dirty air ducts can cause musty odors.

The microbes that cause musty odors love dark, moist environments. Add in some dust and grime, and your ductwork will, sooner than later, become mold and mildew’s best bud. HVAC professionals can snake a tiny camera through your ductwork to scope out trouble spots that need attention. 

According to the Environmental Protection Agency (EPA), you should consider having your ducts serviced if:

• You can see mold in your ducts or any other component of your HVAC system.
• You have a pest problem in your ducts, such as insects or rodents.
• Your ducts are plugged with dust or you see dirt particles coming from your HVAC registers.

Clogged drains can cause musty odors.

HVAC systems create significant condensation—which is why there’s a drain near your unit. If the drain gets plugged up, moisture can seep into your duct work. Excess moisture can also back up into the evaporator coil pan and accelerate mold growth. Try using a wet-dry vac to clean out the drain line. If that doesn’t seem to help, call in a Denver HVAC professional.

A dirty evaporator coil can cause musty odors.

In case you haven’t noticed the theme here, it’s moisture + dirt = musty smell. The same goes for a dirty evaporator coil. To clean the coil:

• Turn off your HVAC unit and carefully remove the access panel to expose the coil.
• Gently vacuum the fins and coils with a soft brush attachment.
• If you notice any bent fins, use a screwdriver to straighten them back out.
• Spray the coil with a solution made of 1 part bleach to 10 parts water and gently wipe them clean. Do not use undiluted bleach, as that will damage the metal. Also, most hardware stores sell evaporator coil cleaner.
• Remove the evaporator pan and clean that as well.
• Put everything back together, and turn your unit back on.

Sick of That Musty Smell? We Can Help!

Many homeowners are uncomfortable working on their HVAC units—for good reason. We’re happy to come check out your system to identify what’s causing your musty odor. We’ll answer all of your questions, show you exactly what we’ve found, and be upfront about what it’ll cost to fix it.

You deserve to enjoy a fresh-smelling home. We can help! To get started, just give us a call.