A furnace that will not heat can feel scary, especially if you have never had one fail. Winters in the San Antonio area are mild, so many homeowners go months without thinking about their heating system. Then a cold snap hits and the house stays chilly.
Mofactor Heating & Air is a referral service. The work itself is done by independent local providers in our network, not by us. This page explains the basics in plain words, then helps you connect with a provider. You can learn what to check first, what a repair visit looks like, and which questions to ask before you agree to anything. Requesting an estimate carries no obligation, so you can compare your options at your own pace.
Smell Gas? Put Safety First
A rotten egg smell can mean a gas leak. Do not flip switches, light a flame, or use your phone inside. Walk everyone out of the house, including pets. Once you are outside, contact your gas utility or local emergency number.
Do not go back in until you are told it is safe. A furnace repair can wait. Your safety cannot.
Carbon Monoxide Alarm Sounding
A carbon monoxide alarm is a serious warning. Get everyone into fresh air and call emergency services. Headaches, dizziness, and nausea in several people at once are also warning signs.
Keep the furnace off until a provider has inspected it. Never silence the alarm and carry on.
Quick Checks Before You Call
Some furnace problems have simple causes. Try these steps first. They take a few minutes and need no tools.
Look at the Thermostat
Make sure it is set to heat and that the target is higher than the room temperature. Dead batteries are a common culprit. Swap them for fresh ones if your model uses them.
Check Power and Switches
Many furnaces have a switch that looks like a regular light switch, often near the unit. Someone may have flipped it by accident. Also check the breaker panel for a tripped breaker. Reset it once only. If it trips again, stop and leave it alone.
Swap a Clogged Filter
A dirty filter chokes airflow. That can make the furnace overheat and shut itself off. If your filter looks gray and furry, replace it.
Confirm the Gas Supply
If you have a gas furnace, check that the valve near it is open and that other gas appliances work. Do not try to relight anything you are unsure about.
Common Signs Your Furnace Needs Repair
Some problems are loud. Others creep in. Here is what to watch for, from most urgent to least.
Warning Signs to Treat Seriously
- A yellow or flickering flame instead of a steady blue one
- Soot or scorch marks around the unit
- A burning smell that does not fade after the first startup of the season
- Banging or scraping sounds
Turn the system off and ask a provider to look at it.
Signs That Can Wait a Few Days
- Uneven heat from room to room
- The furnace turning on and off in short bursts
- Higher energy bills with no change in habits
- Air that feels weak coming from the vents
These still need attention, but they are less urgent.
What Happens During a Furnace Repair Visit
Knowing the routine takes away the nerves. A provider will usually ask when the problem began and what you have noticed. Then they inspect the unit, test the safety controls, and find the cause.
They should explain the problem in simple words and show you the worn part if they can. You should get a written price before work begins. Many repairs can be done in one visit if the part is on the truck.
Common Furnace Repairs
Most heating calls come down to a handful of parts.
- Igniter or pilot: the part that starts the flame
- Flame sensor: a small rod that gets dirty and shuts the burner off
- Blower motor: moves warm air through your ducts
- Control board: the brain that runs the startup steps
- Thermostat: sometimes the fault is the wall control, not the furnace
Costs for these differ a lot, so see the table on this page.
Repair or Replace Your Furnace?
A repair makes sense when the unit is fairly young and the fix is modest. Replacement may be worth a look when repairs pile up, the unit is old, or a major part like the heat exchanger has failed.
Age and Repair History
Many furnaces last 15 to 20 years with care. If yours is near that range and keeps breaking, ask for a replacement quote next to the repair quote. Searching for furnace replacement near me is a fine place to start, but compare written numbers, not just search results.
Comfort and Efficiency
Older units can run unevenly and cost more to operate. Ask a provider what a newer model could change in your home. Some of this is hard to measure, so ask for plain answers.
Questions to Ask the Provider
Ask before you sign. Good questions protect you and keep things calm.
- Is the provider licensed in your state, and can they share the number?
- Do they carry liability insurance?
- Will you get a written quote that lists parts and labor?
- Is there a warranty on parts and on workmanship, and for how long?
- What caused the failure, and can they point to it?
What a Good Answer Sounds Like
A good answer is clear, patient, and specific. The provider explains the options, including doing nothing for now, and gives you time to decide.
Red Flags to Watch For
- Pressure to decide on the spot
- A vague price with no paperwork
- Insisting the whole system is dead without showing you why
- A request for full payment before any work starts
HVAC service should feel like a conversation, not a sales race.
Keeping Your Heating and Cooling Ready
Since the mild winters here mean the furnace sits idle for long stretches, a check before the first cool spell can catch problems early. Replace filters on schedule, keep vents clear, and keep the area around the unit clear of boxes and stored items.
Take It One Step at a Time
Cool house, calm mind. Do the safety steps, try the quick checks, and then reach out. Request a callback to talk about providers in our network, or use the request form to ask for an estimate with no obligation.
What's Included
Safety Check
A provider checks the flame, venting, and safety controls before they decide what needs fixing or leaving alone.
Clear Diagnosis
They find the cause and explain it in plain words, not a list of unfamiliar terms.
Written Quote
You see parts and labor on paper before any repair work begins at your home.
Repair Work
The provider replaces or cleans worn parts, then tests the furnace to confirm it heats and runs safely.
Typical Furnace Repair Costs
Prices vary by home, part, and provider. These are typical U.S. ranges only, not quotes. Always ask for a written quote that lists parts and labor before you agree to any work.
| Repair item | Typical range | Notes |
|---|---|---|
| Diagnostic visit | $75 – $200 | Often applied toward the repair if you proceed |
| Flame sensor cleaning or swap | $75 – $300 | Common fix when the burner shuts off early |
| Igniter replacement | $150 – $500 | Price depends on the furnace model |
| Blower motor repair | $300 – $1,000 | Higher for variable-speed motors |
| Control board replacement | $300 – $900 | Parts availability can affect the price |
| Heat exchanger repair | $1,500 – $3,500 | Often leads to a replacement discussion |
How It Works
Stay Safe First
If you smell gas or hear a carbon monoxide alarm, leave the house and contact emergency help.
Try Quick Checks
Look at the thermostat, switch, breaker, and filter before you reach out to anyone.
Request Help
Request a callback or fill in the request form to be matched with a provider.
Compare and Choose a Provider
Review the written quote, ask your questions, then decide what feels right.
Why Call Mofactor Heating & Air
Plain Answers First
Learn what is happening and what to ask before you speak with any provider.
Local Providers
Independent providers in our network serve homes across the area.
Compare Quotes
Request an estimate and compare written numbers at your own pace.
No Pressure
Asking carries no obligation, so you can decide when you are ready.
Other Services
Need home furnace repair in San Antonio?
Tell us what your system is doing. A local provider in our network can follow up with next steps. Request an estimate with no obligation, or send a note to contact@mofactor.living.
Home Furnace Repair FAQ
Why is my furnace blowing cold air?
A few causes are possible, such as a thermostat set to fan only, a dirty filter, a tripped switch, or a flame sensor that needs cleaning. If checks do not help, ask a provider to inspect it.
How much does furnace repair usually cost?
Many repairs fall between about $150 and $1,000 in the U.S., depending on the part and the job. Major parts cost more. Ask for a written quote first.
Should I repair or replace my old furnace?
If the unit is near 15 to 20 years old and breaks often, replacement may make sense. Ask for both quotes and compare them in writing before you decide.
Get in touch
Tell us what your system is doing. A local provider in our network can follow up with next steps. Request an estimate with no obligation, or send a note to contact@mofactor.living.
No obligation