Why is my furnace running but not blowing warm air?
Check the thermostat and replace a dirty filter first. If air stays cool, the cause may be a failed igniter, a flame sensor, or a tripped safety switch. A provider can test it safely.
Request an estimate today
A furnace rarely quits without warning. It rattles. It blows weak air. Your bill creeps up. Those are the early signs, and they are usually the easiest and least costly time to act. Currentseeing Heating & Air helps you catch the problem early.
Currentseeing Heating & Air is a referral service. It does not repair furnaces. It connects homeowners in the Birmingham area with independent providers in our network. Winters here are mild, so many furnaces sit idle for months and then fail on the first cold night. Send an estimate request, and a local provider contacts you to talk through the problem and plan the visit around your week. If you prefer to talk, Request a callback to check provider availability. Ask for a written quote before any work begins, since costs vary by job.
If you smell gas, leave the house. Do it before anything else. Do not flip switches, use a lighter, or start the furnace.
Once you are outside, contact your gas utility or emergency services from a safe spot. Do not go back in until you are told it is safe.
A headache, nausea, or a carbon monoxide alarm going off also means: get out, then get help. Burning smells, smoke, or soot near the furnace are also reasons to shut it off and step away.
Some furnace problems are small. Try these first. They take a few minutes.
Make sure it is set to heat. Set the temperature a few degrees above the room. Swap the batteries if the screen is dim or blank.
A clogged filter chokes airflow. The furnace then overheats and shuts itself off. If the filter looks gray and thick, replace it.
Look at the breaker and the switch near the furnace. It often looks like a light switch. Make sure both are on.
Walk the house. Open the registers. Move rugs and furniture off them. Blocked vents make rooms feel cold even when the furnace runs.
If none of that works, stop there. Do not open panels or touch gas lines.
Catch it early. A small fix now often beats a big one in January. Watch for these.
Banging, squealing, rattling, or scraping all mean something is loose, worn, or dirty. Do not wait for the noise to stop on its own. It will not.
If the air is faint or some rooms stay cold, the blower, filter, or ducts may be the cause. Ducts in a hot attic can also leak, which wastes heat.
Does the furnace turn on and off every few minutes? That is a sign of overheating, a bad sensor, or a sizing issue. It wears parts fast.
Same weather, higher bill. The furnace is working harder to do the same job. Something is off.
A healthy gas flame burns steady and blue. A yellow flame can point to a combustion problem. Treat it as a safety issue and have a provider look.
Noticed one or two of these? Request a callback to check provider availability.
The provider starts by asking what you have seen and heard. Then they inspect the furnace, test the controls, and check safety switches, airflow, and the flame.
You should get a plain explanation of what failed and what it costs. Ask for it in writing before work begins. Simple repairs may be done during the same visit if parts are on the truck. Others need a part ordered.
These come up often in homes across the Birmingham area.
Many of these are smaller jobs when caught early. A worn part left alone can strain others.
Answer first: repair if the furnace is fairly young and the fix is modest. Replace if it is old, repairs keep stacking up, or a major part has failed.
Some rules of thumb. A furnace past 15 years old often costs more to keep alive. A cracked heat exchanger is usually a replacement job. If a repair quote is close to half the price of a new unit, ask the provider about the numbers.
Searching furnace replacement near me? A provider can quote that too, and compare it with the repair. Good heating and cooling advice covers both options, not just one.
It is smart to have the furnace looked at while the weather is warm. Also, if your AC quits in a heat wave, that is Emergency AC repair, and it has its own page on this site.
Busy household? Say so when the provider calls. Ask about morning or afternoon windows, how long the heat will be off, and whether a space heater is safe to use meanwhile.
Plan around your week. A little notice helps a provider schedule HVAC service when someone is home to open the door.
The provider checks the flame, vents, and safety switches so the furnace runs safely, not just warmly.
They test the igniter, sensors, and controls to find why the heat stopped.
Filters, blower, and ducts get a look, since weak airflow is a common early warning.
You get a plain explanation of the problem and the cost in writing, with repair and replacement options if both make sense.
These are typical U.S. ranges. Real prices vary by furnace type, part, and home. Always get a written quote before you approve any work.
| Repair item | Typical range | Notes |
|---|---|---|
| Diagnostic visit | $75 – $200 | Some providers apply it to the repair |
| Igniter or flame sensor | $100 – $450 | Common cause of startup trouble |
| Thermostat repair or swap | $100 – $350 | Varies with smart models |
| Blower motor or capacitor | $300 – $1,000 | Motor costs more than capacitor |
| Control board | $300 – $800 | Depends on make and age |
| Heat exchanger repair | $1,500 – $3,500 | Often leads to replacement talk |
Fill out the short estimate form. Tell us what you see, hear, or smell.
A local provider in our network contacts you to talk through the problem.
Get the scope and price in writing. Ask questions before you agree.
Pick a window that suits your household, and the provider does the work.
We focus on noises, weak airflow, and rising bills, so small problems get looked at before they grow.
Independent providers in our network know the heating and cooling needs of homes here.
Start with a short form. No obligation, and no phone tag.
Tell the provider your routine and plan the visit around your week.
Tell us what your system is doing. Request an estimate and a local provider in our network will follow up. Prefer the phone? Request a callback to check provider availability.
No obligationCheck the thermostat and replace a dirty filter first. If air stays cool, the cause may be a failed igniter, a flame sensor, or a tripped safety switch. A provider can test it safely.
Not for long. Banging or squealing often means a worn part. Turn it off if noise is severe or you smell anything odd, then request an estimate.
Age over 15 years, frequent repairs, rising bills, or a cracked heat exchanger all point to replacement. Ask a provider to compare repair and replacement costs in writing.
Tell us what your system is doing. Request an estimate and a local provider in our network will follow up. Prefer the phone? Request a callback to check provider availability.
No obligation