HVAC emergency guide: heating and cooling failures
An HVAC failure is an emergency when it puts people at risk: no heat in freezing weather, no cooling in extreme heat for vulnerable people, a gas smell, a CO alarm, burning smells or smoke from the equipment, or water from the system reaching electrical parts. Many other failures can wait for a scheduled visit. Call 833-877-1717 to request an independent HVAC provider.
RepairNowUSA editorial review · Last substantively reviewed October 13, 2026 · Review standards
Safety emergencies: act first
- Gas smell near a furnace or water heater: leave the building, do not touch switches, call 911 or the gas utility from outside.
- Carbon monoxide alarm: get everyone out to fresh air and call 911. Do not go back inside until responders say it is safe.
- Burning smell or smoke from the furnace or air handler: turn the system off at the thermostat and the breaker. If there is smoke or flame, leave and call 911.
- Water from the unit reaching wiring: turn the system off at the breaker from a dry spot.
A dusty smell the first time the heat runs in fall is common and usually fades quickly. A smell like hot plastic, melting wire or rotten eggs is different.
Comfort failures: how urgent?
- No heat in freezing weather: urgent, both for people and for pipes. See our no-heat guide.
- No cooling in extreme heat: urgent for infants, older adults and people with medical conditions. See our heat wave guide.
- Reduced performance: the system runs but struggles. Usually schedule soon rather than tonight. See our not-cooling guide.
- Noises: a new grinding, screeching or banging noise means turn it off and call soon, since running it can turn a small repair into a big one.
- Water leaks: turn the system off and check the condensate drain and float switch.
Five checks that solve many no-heat and no-cool calls
- Thermostat mode, set temperature and batteries.
- Breakers for the indoor and outdoor units (reset once only).
- The furnace or air handler service switch.
- The air filter.
- The condensate drain or float switch, which shuts the system down when water backs up.
Know your system
- Gas furnace with central AC: indoor furnace with a blower, outdoor condenser for cooling.
- Heat pump: the outdoor unit heats and cools; backup electric heat helps in cold weather.
- Boiler: heats water or steam for radiators or radiant floors. Low water pressure and pump problems are common.
- Ductless mini-split: wall-mounted indoor heads with an outdoor unit; blinking lights often show error codes.
- Packaged unit: everything in one outdoor or rooftop cabinet, common in commercial buildings and some homes.
The model and serial numbers on the unit's label help a technician bring the right parts.
Repair or replace?
For major failures, such as a compressor, heat exchanger or a system well past its expected life, ask the provider for both repair and replacement prices. Age, refrigerant type, efficiency and how often the system has failed recently all matter. A cracked heat exchanger is a safety issue because it can leak combustion gases.
Getting help
When you call 833-877-1717, describe the system type, what it is doing and who is in the building. RepairNowUSA looks for a participating independent HVAC provider in your area. The provider confirms timing, diagnostic fees and repair pricing with you.
How RepairNowUSA can help
Call 833-877-1717 and describe what is happening and the property ZIP code. RepairNowUSA looks for a participating independent provider for that kind of work in your area and connects you if one is available. The provider confirms timing, scope and price with you and does the work. Availability and response times vary and are not guaranteed.
Call 833-877-1717Common questions
What counts as an HVAC emergency?
Gas smells, carbon monoxide alarms, burning odors or smoke, and loss of heat or cooling during dangerous temperatures, especially for vulnerable people. Most performance problems can be scheduled.
Should I turn my HVAC off if it makes a loud noise?
Yes. New grinding, screeching or banging usually means a mechanical problem, and running it can cause more damage. Turn it off and call for service.
Why does my HVAC system keep shutting off?
Common causes are a dirty filter causing overheating, a tripped float switch from a clogged drain, a failing flame sensor on a furnace, or electrical faults. Repeated shutdowns need a technician.
How much is an emergency HVAC call?
Independent providers set their own pricing. Many charge a diagnostic or after-hours fee. Ask for the fee and how repairs are priced before you approve the visit.
Can I call any time?
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.
Authoritative references
These public sources give general safety context. They do not replace an on-site evaluation, and RepairNowUSA does not perform the work.