Thermostat and switch
Heat mode, set point above room temperature, furnace switch on.
Gas furnace not heating correctly?
A gas furnace that will not heat, short-cycles, makes noise or smells unusual needs a technician. Gas and carbon monoxide safety come first. Check the thermostat, switch and filter, then call 833-877-1717. RepairNowUSA connects the request. An independent HVAC technician does the repair.
Am I in the right place?Yes for no heat, weak heat, short cycling, unusual noises, or soot around the furnace.
Is this urgent?Yes in cold weather. If you smell gas, leave the building without switching anything on or off and call the gas utility or 911 from outside. If a carbon monoxide alarm sounds, get everyone out and call 911.
What do I do next?Do the safe checks below, then call 833-877-1717.
Will not ignite: furnace ignition. General furnace help: furnace repair.
RepairNowUSA editorial review · Last substantively reviewed October 13, 2026 · Review standards
Safe checks
Filter
Replace a dirty filter. Overheating shuts furnaces off.
Vents outside
High-efficiency furnaces vent through PVC pipes outside. Snow or debris blocking them can shut the furnace down.
Carbon monoxide
If you smell gas, leave the building without switching anything on or off and call the gas utility or 911 from outside. If a carbon monoxide alarm sounds, get everyone out and call 911. Soot, scorch marks or yellow flames are warning signs to report.
Common gas furnace problems
Ignition failure
See ignition repair.
Short cycling
Overheating, a flame sensor or venting issue.
Noisy operation
Blower, inducer or burner problems.
Cracked heat exchanger
A serious safety issue found by the technician.
What to have ready when you call
- Property ZIP code, home or business
- What the furnace does
- Error-light blinks
- Any smells, soot or CO alarms
- Furnace brand and age
- Indoor temperature
What happens when you call RepairNowUSA
- Describe what is happening in plain words and give the property ZIP code. You do not need to know which trade to ask for.
- RepairNowUSA checks for a participating independent provider who handles gas furnace repair in that area.
- If one is available, you are connected. The provider confirms timing, access, scope and price with you before any work.
- The provider, not RepairNowUSA, diagnoses and performs the repair.
RepairNowUSA is a referral and connection service. Provider availability and response times vary by location, time and demand, and are not guaranteed. Before you approve work, ask what was found, the price, the timing and what is not included.
Call 833-877-1717Gas furnace questions
Why does my gas furnace keep shutting off?
Common causes are a dirty filter, a dirty flame sensor, blocked vents or a failing safety switch.
Is a yellow flame a problem?
Furnace burner flames should be mostly blue. A yellow or flickering flame can signal incomplete combustion; have it checked.
Can I call at night?
Yes. You can call 833-877-1717 at any time, including nights, weekends and holidays. Whether an independent provider can come out right away depends on your ZIP code, the time and provider capacity, so availability is not guaranteed.
Do providers work on all furnace brands?
Independent HVAC providers commonly work on major brands such as Carrier, Trane, Lennox, Rheem, Goodman, Bryant and York. Tell RepairNowUSA the brand on the call. RepairNowUSA is not affiliated with or authorized by any manufacturer, and warranty work may need the manufacturer’s own network.
Authoritative references
These public sources give general safety context. They do not replace an on-site evaluation, and RepairNowUSA does not perform the work.