Most of the time, when your heating or cooling system stops doing what it’s supposed to, the cause isn’t some catastrophic failure. It’s something basic—a setting that slipped, a filter long past due, a blocked drain nobody thought about since last summer. You’d be surprised how often we walk into a call and find a fix that takes under five minutes.
If you like handling things yourself (at least the first pass), here are a few problems worth checking before you make that call.
“Why won’t my system turn on?”
Start simple. Look at the thermostat. If the screen’s blank, you may need to swap the batteries. If it’s on, double-check the mode and temperature—someone might’ve adjusted it without realizing it.
Still nothing? Go to the breaker panel. If the system’s breaker is tripped, flip it back once. If it trips again right away, stop there. That’s a job for a technician.
“Why is the airflow so weak?”
The first thing we always ask: when did you last change the filter? A clogged one doesn’t just block air—it can also trigger safety shutoffs or make the whole system feel underpowered. Replacing that filter might solve the issue if your vents are blowing less than usual.
Take a walk around your home, too. Make sure vents aren’t closed or blocked by furniture. If everything’s open and you’re still getting weak airflow, it could indicate something deeper, like a blower issue or duct problem.
“Why is one room freezing while another’s warm?”
Sometimes it’s airflow, sometimes insulation, and sometimes it’s just where the room sits in the house.
Rooms above garages or those with lots of windows tend to lose heat faster. You might not need to adjust the system. Just sealing up drafts or adding a curtain that holds heat better could resolve the issue.
If one room consistently feels different and there’s no obvious reason, it might be worth having the system balanced. We see this often in older homes or additions where airflow wasn’t evenly planned out.
“Why is my AC freezing up or turning off?”
If it’s hot out and your AC stops running—or worse, starts icing over—it’s usually a sign of trouble with airflow or drainage. A dirty filter can choke the system and lead to frozen coils. So can a clogged drain line.
Try swapping the filter first. If you’re comfortable doing so, check the drain line for blockages or standing water. Pouring a bit of vinegar through the pipe can help clear light buildup. But if things still aren’t moving or the ice comes back, stop running the unit and schedule a service call.
“What’s that sound supposed to be?”
HVAC systems do make noise, but it shouldn’t be dramatic. A soft hum, the whoosh of air, maybe a click as it kicks on—that’s normal. What isn’t? Grinding, buzzing, banging, or anything that sounds sharp or metallic.
If it started recently, you can check the access panel and nearby ductwork. Sometimes a loose screw or a vibrating register makes more racket than you’d expect. But if the sound keeps going and you can’t find the cause, don’t let it run too long. Strange noises usually mean something inside is wearing out.
“Why does it smell weird when the air kicks on?”
A little dust burning off at the start of the heating season is normal. A musty smell, though, usually means moisture. Could be mold near the coil, standing water in the drain pan, or something growing in the ductwork if it’s been a while since a cleaning.
Flushing it with vinegar is a good place to start if you can reach the drain line. Beyond that, it’s worth having a tech look at the indoor coil and pan. Those are areas where moisture hangs around, and they can start causing trouble if left unchecked.
“Could something outside be the problem?”
Absolutely. Your outdoor unit needs breathing room. If it’s packed in with leaves, cottonwood, or landscaping, it’ll have to work harder—and less efficiently—to move air.
Clear out the space around it, especially in spring and fall. If the fins are visibly dirty, you can gently brush them off; just don’t use a hose or anything with pressure. If you notice the fan struggling or hear a strange hum outside, that’s your cue to call..
When to Let a Pro Step In
At Schwantes, we don’t jump straight to replacing things. If it’s an easy fix, we’ll tell you. And if it’s not, we’ll explain what’s going on in plain terms—so you can make a decision without guessing.
