If your heater won’t turn on, start by checking the thermostat, power supply, and air filter. Many heating issues come from simple fixes, but others signal that your system needs professional repair. Here’s how to narrow down what’s happening and when it’s time to call the experts at C-U Trade Services.

When the temperatures drop in Central Illinois, a heater breakdown can’t wait. Whether you have a gas furnace or a heat pump, these are the most common reasons for heating failure and what you can do about them.

Common Reasons Your Heater Stops Working

Thermostat Problems

If your system isn’t running, the thermostat is the first thing to check. Make sure it’s set to “heat,” the temperature is higher than the current room temp, and the batteries aren’t dead. If it’s still not responding, the wiring or communication between the thermostat and the furnace might be disrupted.

Power or Electrical Issues

A tripped breaker or blown fuse is a common reason heaters won’t start. Check your home’s electrical panel and the switch near your furnace or air handler to make sure they’re on. If resetting doesn’t help, the problem could be internal, such as a shorted control board or a faulty capacitor, and should be handled by a technician.

Dirty or Clogged Air Filter

Restricted airflow is one of the biggest causes of heating problems. A dirty air filter can cause your system to overheat and shut down as a safety precaution. Replace your filter every 1 to 3 months and check that the return vents are open and unobstructed.

Blocked Vents or Ductwork

Closed or blocked vents make it difficult for your system to circulate warm air. If only some rooms are cold, check the registers and return vents first. In older homes, collapsed or leaking ductwork can also cause poor performance.

Ignition or Flame Sensor Failure

For gas furnaces, the ignitor or flame sensor may be to blame. If the flame sensor is dirty, the furnace may light and then shut off quickly. This is a safety feature to prevent the buildup of unburned gas. These parts can often be cleaned or replaced during a service visit.

Heat Pump or Refrigerant Issues

If your home uses a heat pump, low refrigerant or a failed reversing valve can keep it from switching into heating mode. Frozen coils or worn components can also cause the system to blow cool air. Because refrigerant handling requires certification, it’s best to leave this diagnosis to a professional.

Lack of Routine Maintenance

Most heating failures start small. Skipping seasonal maintenance allows dust and wear to build up until a critical part fails. Scheduling yearly tune-ups helps catch these issues early and keeps your system running safely and efficiently.

When It’s Time To Call a Professional

If you’ve checked the basics and your heater still isn’t working, it’s time to call an HVAC technician. Signs that you need professional help include:

  • Strange smells like burning or gas
  • The system will short-cycle or won’t stay on
  • The thermostat is fine, but no warm air blows
  • The furnace or heat pump makes unusual noises

At C-U Trade Services, our licensed HVAC technicians handle repairs for all makes and models across Champaign, Urbana, Danville, and the surrounding Central Illinois areas. We’ll find the issue, make the fix, and get your heat running again quickly.

How To Prevent Future Heating Problems

Staying ahead of heating breakdowns is the best way to avoid surprises when the cold hits.

  • Schedule a fall tune-up each year.
  • Replace your filter regularly and keep vents open.
  • Don’t ignore unusual noises or short cycling.
  • Ask about our Peace of Mind Plan for priority scheduling and repair discounts.

If you’re planning a remodel or home addition, it’s a great time to update ductwork or replace older systems for better efficiency. Our construction company at C-U Under Construction coordinate seamlessly with our HVAC team to make those upgrades simple.

Need Heating Help in Central Illinois?

If your heater still isn’t running, let our team take it from here. C-U Trade Services provides fast, reliable heating repair and maintenance for homes and businesses throughout Central Illinois.