Why Is My HVAC Not Cooling? Colorado Springs Troubleshooting Guide

70% of HVAC cooling failures in Colorado Springs are caused by thermostat settings, clogged filters, or tripped breakers—issues you can diagnose and fix yourself in under 5 minutes before calling a technician.

Key Takeaways

• Air filters in Colorado Springs last 2-3 weeks during cottonwood season (May-June), vs. normal 60-day lifespan.
• A clogged filter causes evaporator coil freeze-over, stopping cooling entirely within 30-60 minutes.
• Spring HVAC tune-ups prevent 70% of seasonal cooling failures caused by debris buildup.
• Capacitor failures typically occur at 8-12 years; replacement is a professional repair due to lethal electrical charge.

What should I check first if my HVAC isn't cooling?

1. Thermostat Mode and Settings

This sounds obvious, but it happens. Make sure the thermostat is set to COOL and not HEAT or just FAN. Check that the temperature setpoint is actually below the current room temperature. If it's set to 74°F and the room is 73°F, the system isn't going to run.

Also check if someone switched it to FAN ONLY. In fan-only mode, air moves but no cooling happens. Easy to fix.

2. The Air Filter

Pull the filter out and hold it up to a light. If you can't see light through it, restricted airflow is almost certainly making your problem worse. A completely clogged filter causes the evaporator coil to freeze over, which stops cooling entirely even though the system runs.

Replace the filter. Then turn the system to FAN ONLY (not cool) for 30 to 60 minutes to thaw any ice on the coil before switching back to cooling mode.

In Colorado Springs during cottonwood season (late May through June), this is extremely common. Filters that would normally last 60 days can mat up in 2 to 3 weeks. Check yours first.

3. Circuit Breaker

Head to your electrical panel. Look for two breakers labeled HVAC, AC, or AIR HANDLER. They should both be in the ON position. If one has tripped to the middle or OFF, reset it fully to OFF and then back to ON.

If it trips again within minutes of the system running, don't keep resetting it. That's a sign of a real electrical problem. Call a tech.

4. Outdoor Unit Not Running

Go outside and look at the condenser unit. Is the fan spinning? Is the unit making any sound at all?

If the outdoor unit is completely silent while the thermostat is calling for cooling, you likely have a failed capacitor, a tripped disconnect, or a contactor issue. These are pro-level repairs.

If the fan is running but blowing warm air up, and the refrigerant lines going into the unit feel warm instead of cold, low refrigerant or a dirty coil is likely.

What are common professional-level HVAC cooling problems?

Dirty Condenser Coils (Extremely Common in Colorado Springs May-June)

The outdoor condenser coil needs clear airflow to reject heat. Cottonwood fluff accumulates on these fins fast, and once it builds up it acts as insulation, trapping heat inside the unit. The system runs, pulls power, but can't shed the heat from your home.

You can gently rinse the exterior of the coil with a garden hose (power off first), spraying from top to bottom. But if cottonwood has packed into the fins tightly, a professional coil cleaning with the right tools will do a much more thorough job.

This is why a spring tune-up before cottonwood season is worth its cost in Colorado Springs. See our seasonal tune-up service.

Failed Capacitor

The capacitor gives the compressor and fan motors the electrical boost they need to start. Capacitors fail from heat and age, typically around the 8 to 12 year mark on a system.

Symptoms: the outdoor unit hums but doesn't start. The fan may spin weakly or not at all. You might notice the system starting and immediately stopping. Sometimes you can hear a faint hum from the unit without real operation.

Capacitor replacement is a pro repair. The part is cheap, but capacitors store a lethal electrical charge and need to be handled correctly.

Low Refrigerant (Leak)

Refrigerant doesn't "run out" like fuel. If you're low, there's a leak somewhere in the system. The fix isn't just topping it off. A proper repair means finding the leak, fixing it, and then recharging to the correct pressure.

Signs of low refrigerant: the system runs constantly but can't reach the set temperature. Ice forms on the refrigerant lines near the indoor unit. The air blowing from vents isn't as cold as it used to be. And at Colorado Springs' altitude, refrigerant connections see more stress than at sea level, so leaks aren't unusual on older systems.

Adding refrigerant without fixing the leak is a temporary patch that won't hold.

Frozen Evaporator Coil

If airflow is restricted (dirty filter, blocked registers) or refrigerant is low, the evaporator coil inside the air handler can freeze solid. When this happens, the system can't exchange heat at all.

You might notice ice on the refrigerant line near the indoor unit, or water dripping from the unit as ice melts.

Turn the system off, leave the fan running, and wait 1 to 2 hours for the ice to fully melt before restarting. But understand that freezing is a symptom. If it comes back, there's an underlying cause that needs fixing.

When to Call Immediately vs. Wait-and-See

Call today: outdoor unit won't start at all, breaker keeps tripping, ice on refrigerant lines, water dripping inside the home, system running more than 20 minutes continuously without cooling the space even slightly.

Wait-and-see (try the DIY checks first): system is cooling but slower than expected on a record-hot day (above 95°F, systems can struggle to keep up), filter is dirty and you haven't replaced it yet, thermostat was set wrong.

If you've worked through this list and the problem isn't resolved, contact us and we'll get a tech out to diagnose it properly. For complete AC service, see our AC repair page.