Your home will become uncomfortable if your heater won’t turn on and stay on. The problem can be the thermostat, power supply, or air filter. It can be an open gas valve or a faulty pilot light.
HVAC technicians can correct these problems after troubleshooting your heater. Continue reading and find out the six reasons your heater won’t turn on.
Common Reasons Your Heater Won’t Turn On
HVAC problems can stop your heater from coming on and heating your home. Here are some reasons why it won’t turn on:
1. Check For Thermostat Problems
Checking the batteries and the temperature setting can rule out thermostat problems. You must replace the batteries and follow the temperature recommendations.
Your living space won’t be comfortable if the temperature is set too low. You’ll need an HVAC professional if the problem is the calibration or faulty wires.
2. Tripped Circuit Breaking or Blown Fuse
Let a technician know where the breaker stops when it trips. You can replace a blown fuse. More serious problems are caused by overloaded circuits and power surges.
3. Dirty Air Filter Can Stop the Heater From Engaging
Air filters can cause airflow restriction and overheating. Changing filters regularly to keep the heater cleaner.
However, call a professional if the system automatically shuts down to mitigate serious risks.
4. Test For Pilot Light or Ignition System
Make sure the pilot light is lit, and the ignition is engaging. Pilot lights go out because of drafts and if they become dirty.
The thermocouple can also malfunction and stop proper gas flow. Hire a professional to check the electric ignition. If it’s cracked or dirty, it could fail.
5. Look For a Loose Furnace Door or Test For Safety Switch Triggered
Close the access panel if it’s open. The heater won’t engage if the door is open. Check the safety switch. If it shuts off, hire an HVAC technician to find the problem.
6. Dirty Flame Sensor or Overheating Issues
HVAC technicians can look for carbon buildup on the flame sensor. Sometimes, cleaning it can fix the problem.
It can make the heater overheat if the sensor is dirty. Restricted airflow can also engage safety features.
Step-By-Step Troubleshooting Guide
HVAC technicians troubleshoot the heater to find the problem. Here are a few steps they will follow:
1. Check the Thermostat For Problems
They’ll make sure the heater is on heat mode. The technicians adjust the thermostat by a few degrees to get the heater to engage.
They’ll replace old batteries to rule out related issues. They may also reset the thermostat.
2. Test the Heater’s Power Supply
The power supply can cause heater problems. Technicians check for tripped breakers, and they’ll reset the furnace switch if it’s off. They can also replace blown fuses and check the gas valve.
3. They Will Replace Dirty Air Filter
Your heater won’t come on if the air filter is dirty. Install a clean air filter monthly.
4> Examine the Pilot Light or Ignition System
The technician can relight the pilot light. They can inspect the electronic ignition.
The technicians will clean it if it’s dirty and replace it if it’s faulty. You should call a pro if your pilot light won’t stay on or if the ignition is failing.
5. Inspect Access Panel Door or Test the Heater’s Safety Switch
The heater won’t start if the access panel door is open. The technicians check the safety switches if the door won’t stay closed. They’ll test the heater for problems if the door stays open or is loose.
6. Clean the Flame Sensor
The technicians shut off the power and gas before removing the flame sensor. They’ll use an emery cloth to clean the sensor. After they reinstall it, they’ll test the flame sensor for proper function.
When to Call an HVAC Professional
HVAC professionals perform repairs to restore your heating services. Here are signs that you should hire an HVAC professional:
- You smell gas or suspect a gas leak.
- The breaker or fuse trips repeatedly.
- The furnace cycles but doesn’t heat your home.
- The pilot light won’t stay lit, or the ignitor repeatedly fails.
- You notice strange noises or burning smells.
Preventive Maintenance Tips to Avoid Future Heater Issues
Protect your heater by following these preventive maintenance tips:
- You can replace the air filters monthly.
- You should schedule annual HVAC tuneups.
- Make sure the vents stay open and remain unblocked.
- You should get an HVAC technician to test the thermostat seasonally.
- Clean the pilot light and flame sensor.
FAQs About Heaters Not Turning On
Why won’t my heater turn on, but the AC works?
The problem can be the thermostat, power failures, or ignition.
How do I reset my furnace?
Turn off the power supply in the breaker box and press and hold the heater’s reset button for 30 seconds.
Why is my thermostat working, but the heater isn’t?
The problem can be a dirty filter, the thermostat setting, or a faulty component.
Can a dirty air filter stop my heater from working?
Yes, a dirty air filter could cause a blockage and restrict airflow.
Should I try to relight my pilot light myself?
It’s an easy task that doesn’t require a professional unless there’s a major problem.
Call One Hour For All Your Heating Repair Needs
Check the thermostat, power, air filter, and ignition if your heater won’t come on. You can do simple DIY fixes, but you need an HVAC pro for repeated gas or electrical failures.
One Hour offers heater repair services in Pensacola, FL, and surrounding areas. We’re always on time, or you don’t pay a dime.