When your heat stops working, stress spikes fast—especially on a cold night. Take a breath. Most outages are caused by fixable issues you can check safely. Below is a clear, step-by-step guide to get your system running again and to know when it’s time to call Brunswick Isles HVAC LLC.
First: Stay Safe
- Smell gas? Don’t touch switches or use open flames. Leave the home and call your gas utility or 911 from outside.
- Carbon monoxide (CO) alarm sounding or headaches/dizziness present? Go outside immediately and contact emergency services. Learn the basics of CO safety here: CPSC Carbon Monoxide Guide.
- Do not use an oven, grill, or unvented heater for emergency heat.
If none of the above applies, proceed with the checks below.
Quick Fixes Most People Miss
1) Check the Thermostat (Yes, Really)
- Confirm it’s set to Heat, not Cool or Off.
- Set the temperature 3–5°F above the current room temp.
- Replace thermostat batteries if present.
- If you use a smart thermostat, make sure Wi-Fi schedules or Eco modes aren’t overriding heat.
- Slide the Fan setting to Auto, not On, to avoid circulating only room-temperature air.
2) Verify Power to the System
- Find your furnace/air-handler switch (looks like a light switch near the unit). Make sure it’s On.
- Check the breaker panel for tripped breakers labeled Furnace, Air Handler, or Heat Pump. Reset once: OFF → wait 10 seconds → ON.
- Many furnaces have a blower door safety switch; if the panel isn’t seated correctly, the unit won’t run. Reseat the panel firmly.
3) Replace or Reinstall the Air Filter
A clogged filter can shut down modern furnaces and heat pumps.
- Locate the filter at the return grille or inside the air handler.
- Replace if dirty and confirm the airflow arrow points toward the equipment.
- Aim for replacement every 1–3 months (more often with pets or allergies).
4) Open Vents and Returns
- Make sure supply vents aren’t blocked by rugs or furniture.
- Keep return grilles clear and dust-free.
- Closing too many vents can overheat a furnace or freeze a heat pump coil.
Gas Furnace–Specific Checks
Only proceed if you’re comfortable and smell no gas.
- Gas valve: Verify the inline gas valve near the furnace is parallel with the pipe (open).
- Pilot vs. electronic ignition:
- Older units have a standing pilot. If it’s out, follow the manufacturer’s relight instructions printed on the door.
- Newer models use hot surface igniters or spark igniters. If the furnace starts then quits, do not repeatedly reset; call a pro to avoid damage.
- Condensate issues (high-efficiency furnaces): A clogged condensate drain or pump can trip a safety switch. If you notice a full pump reservoir or water around the unit, power it down and call for service.
Heat Pump–Specific Checks (Including Dual-Fuel Systems)
- Outdoor unit iced over? Brief frosting is normal; extended ice buildup is not.
- Gently clear snow/debris around the unit.
- If a solid ice shell forms and doesn’t melt after a defrost cycle (10–15 minutes), shut the system off and call for service.
- Thermostat mode: Make sure it’s on Heat (not Cool or Em Heat unless directed).
- Emergency Heat: If your heat pump fails and you have electric or gas backup, switching to Emergency Heat can keep you comfortable until repairs. Use sparingly—it’s costlier.
- Outdoor breaker/disconnect: Verify the service disconnect by the outdoor unit is in and the breaker hasn’t tripped.
Try a Safe System Reset
- Set the thermostat to Off.
- Turn the HVAC breaker Off for 30 seconds.
- Turn breaker On, wait 60 seconds, then set the thermostat back to Heat.
- Give the system 5–10 minutes to start. Many furnaces and heat pumps run brief self-checks.
Signs You Should Call a Professional Now
Contact Brunswick Isles HVAC LLC if you notice any of the following:
- Repeated breaker trips or electrical burning smells.
- Short cycling (system starts and stops every few minutes).
- Metallic/banging/grinding noises.
- Visible water around the furnace/air handler or frozen lines at the heat pump.
- Furnace runs but blows cold, or heat pump runs constantly without warming.
- You tried the steps above and still have no heat.
We’ll diagnose the root cause—ignition failure, pressure switch faults, flame sensor issues, seized blower motors, control board errors, refrigerant problems, or airflow restrictions—and fix it correctly.
What a Technician Will Check
When you schedule service with Brunswick Isles HVAC LLC, your technician may:
- Pull system error codes and test safety switches.
- Inspect igniters, flame sensors, inducer motors (furnaces).
- Test capacitors, contactors, defrost controls (heat pumps).
- Measure static pressure, temperature rise, and combustion (when applicable).
- Verify refrigerant charge and check for leaks on heat pumps.
- Clear condensate traps/pumps and verify proper drainage.
- Confirm correct thermostat wiring and calibration.
This full approach restores safe operation and helps prevent repeat failures.
Keep It From Happening Again: Pro Tips
- Change filters regularly. Mark your calendar or use reminders.
- Schedule seasonal maintenance. One heating tune-up before cold weather can catch failing parts before they quit.
- Seal the duct system. Leaky ducts waste heat and strain equipment.
- Keep 2–3 feet clear around the outdoor unit; trim shrubs and remove leaves.
- Install a smart thermostat to reduce set-and-forget issues and save energy.
- Upgrade aging equipment. If your furnace is 15+ years old or your heat pump is 10–12 years, consider a planned replacement rather than an emergency one.
- CO detectors on every level and outside sleeping areas; test monthly and replace per manufacturer guidance.
FAQ: Fast Answers
Why is my furnace running but not heating?
Likely causes: tripped gas valve, dirty flame sensor, clogged filter, overheated due to closed vents, or a failed igniter.
Why does my heat pump blow cool air in Heat mode?
Heat pumps deliver gentler, steadier heat than furnaces. If supply air feels cool but the home warms, that’s normal. If the home isn’t warming, look for icing, low refrigerant, or thermostat settings.
Is Emergency Heat bad to use?
No—it’s designed for backup. But it’s less efficient, so use it only until your primary system is repaired.
We’re Here When You Need Us
If your heat stops working, start with the simple checks above. When you need expert help, call Brunswick Isles HVAC LLC. We’ll troubleshoot quickly, explain your options in plain language, and get your home warm again—safely and efficiently.
Want to prevent the next breakdown? Ask about our maintenance plans and heat pump or furnace upgrade options tailored to Carolina coastal homes.
