A Real Story from Our HVAC Techs in New Hampshire
We get this call a lot during New Hampshire’s warmer months: “My AC is running, but it’s blowing warm air. What’s going on?”
If you’ve ever asked yourself that same question, you’re not alone. In fact, just last week, one of our techs, Adam, headed out to a home in Nahsua where the homeowners were dealing with this exact issue. They’d come home from work, expecting a cool house and instead walked into a sauna.
GSMS will talk about what causes this, what you can check yourself, and how we fix it.
Need fast AC help in New Hampshire?
📞 Call us at 603-424-8258 or book an appointment online—we’re here when you need us.
Main Reasons Your AC Unit Might Be Blowing Warm Air
Adam arrived to find the thermostat set to 72, but the temperature inside was creeping toward 80. The AC system was on, the fan was spinning, but the air coming from the vents was warm.
Here’s how Adam walked through the problem and how you can think about your own system if this ever happens to you.
1. Thermostat Settings
First things first. Adam checked the thermostat. It was set to “cool,” but the fan was set to “on” instead of “auto.”
Why it matters: When the fan is set to “on,” it runs constantly, even when the system isn’t actively cooling. That means it might just be blowing air that hasn’t been cooled yet.
Quick fix: Try switching the fan to “auto.” This setting tells your system to blow air only when the air conditioner is actively cooling.
In our Nashua case, the fan was on “auto,” so Adam moved to the next step.
2. Dirty Air Filter
Next, Adam checked the air filter. It was clogged with dust and pet hair.
Why it matters: A dirty filter blocks airflow, which can cause the system to overheat or freeze up. Either way, it can stop cooling properly.
Quick fix: If your filter looks like it’s been through a sandstorm, replace it. Most filters should be swapped out every 1–3 months, especially in homes with pets or lots of dust.
After swapping the filter, the air still wasn’t cool, so Adam kept digging.
3. Outdoor Unit Problems (The Condenser)
Adam headed outside to check the condenser unit. Right away, he noticed the fan wasn’t spinning.
Why it matters: The outdoor unit pulls heat out of your home. If it’s not working, due to a blown capacitor, tripped breaker, or other issue, your AC unit can’t cool the air.
What Adam found: The capacitor was bad. That’s a common part that helps the fan motor start up. Without it, the fan just sits there while your home heats up.
Our fix: Adam replaced the capacitor on the spot, and within minutes, the outdoor unit kicked on and started doing its job. Cool air started flowing again, and the house temperature started dropping.
Real outcome: The homeowners were relieved. They thought they might need a whole new AC system. But with a quick part replacement and a filter change, their system was back in business, without a big bill.
Other Possible Reasons for Warm Air
If none of the above is the culprit, here are a few other things we check:
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Low refrigerant: If your system is low on refrigerant (usually due to a leak), it can’t cool properly.
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Frozen evaporator coil: Sometimes caused by restricted airflow or low refrigerant.
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Electrical issues: Faulty wiring or a tripped breaker can stop parts of your system from running.
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Old or failing system: If your AC unit is over 15 years old, it may just be on its last legs.
What You Can Do Before You Call
Before you pick up the phone, here’s a quick checklist:
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Make sure your thermostat is set to “cool” and “auto”
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Replace or check your air filter
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Look outside and check if the condenser is running? Any weird noises?
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Check your breaker box. Did anything trip?
If you’ve tried all this and your AC system is still blowing warm air, it’s time to bring in the pros at GSMS.
How We Help
When we get calls like the one in Nashua, our priority is to show up fast, figure out what’s wrong, and get your system cooling again, without pushing unnecessary repairs.
We always:
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Explain what we’re doing (in plain English)
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Show you the problem, not just tell you
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Offer real options—repair vs. replace
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Get your air back to cool as quickly as possible
Still Experiencing Warm Air? Let’s Fix That
If your home AC unit is blowing warm air and you’re in New Hampshire, don’t sweat it—literally. Call us at 603-424-8258 , and we’ll get a friendly, knowledgeable HVAC tech (like Adam) out to your home to figure out what’s going on. Or contact us online with any questions.
You don’t have to suffer through a hot house or guess what’s wrong. We’ll bring tools, answers, and cold air!
