Why Won’t My Heater Turn On? 7 Common Issues and Solutions

As the colder months approach, it is important to ensure your heating system is ready to keep your home comfortable and warm. But what do you do when you try to switch on your heater and nothing happens?

After being idle during the summers, many heating units fail to operate properly when they are needed again. This can be due to various reasons, ranging from minor issues like thermostat settings to more significant problems such as ignition failures or electrical faults. 

When your heater doesn’t turn on, it can leave your home chilly and uncomfortable, but the good news is that many of these problems can be identified and resolved with a little troubleshooting.

In this post, we will look at some of the common reasons your heater won’t turn on, along with solutions to get it back up and running.

1. Thermostat Issues Preventing Heater Activation

If the thermostat isn’t set correctly or functioning, the heater won’t receive the signal to start. The thermostat could be set to the wrong mode, such as “Cool” instead of “Heat,” or the temperature setting might be too low to trigger the system.

Troubleshooting Tip: Check the Thermostat Setting

Check the thermostat to ensure it’s set to “Heat,” and adjust the temperature setting to a higher level. If it still doesn’t turn on, check if the thermostat batteries need replacement or if the device itself needs recalibration. 

2. Tripped Circuit Breaker or Blown Fuse Shutting Off Power to the Heater

If the electrical circuit powering your heater is overloaded, it can cause the breaker to trip or the fuse to blow, cutting off power to the unit. This is often overlooked but is a simple fix that can restore power to your heating system.

Troubleshooting Tip: Check the Circuit Breaker or Fuse Box

Go to your circuit breaker panel and look for any tripped breakers. If you find one, reset it by switching it off and then back on. If your home has a fuse box, check for any blown fuses and replace them. If the circuit breaker continues to trip or the fuse blows again, there may be a deeper electrical issue, which a professional should check. 

3. Ignition System Problems Preventing Gas Heater from Starting

A common issue with gas heaters failing to turn on is a problem with the ignition system. Older systems rely on a pilot light to ignite the gas, while newer models often use electronic igniters. If your pilot light goes out or the igniter fails, the furnace won’t ignite, leaving your home without heat.

Troubleshooting Tip: Inspect the Pilot Light or Ignition System

For heaters with a pilot light, check if it’s out. If so, follow the manufacturer’s instructions to relight it safely. For systems with electronic igniters, listen for clicking sounds when the furnace tries to start. If there’s no sound or the igniter appears damaged, it may need replacement. 

In either case, if the issue persists, it’s best to contact an HVAC technician for professional inspection and repair of your furnace.

4. Clogged Air Filters Blocking Heater Operation

Dirty or clogged air filters can prevent proper airflow to your heater, causing it to struggle to turn on or run efficiently. When filters are clogged with dust and debris, the heater may overheat, triggering a safety mechanism that shuts the system down to prevent damage.

Troubleshooting Tip: Check and Replace the Air Filter

Inspect your air filter to see if it’s dirty or clogged. If the filter is covered in dust or debris, replace it with a new one.  A clean air filter allows proper airflow, enabling your heater to operate without unnecessary shutdowns.

We recommend you change your HVAC’s air filter every 1 to 3 months to keep your system running smoothly. 

5. Faulty Blower Motor Preventing Proper Air Circulation

The blower motor pushes warm air through your ductwork and into your home. If the blower motor fails, the heater may turn on, but no warm air will circulate, leaving your home cold. A malfunctioning blower motor can be due to electrical issues, worn-out components, or debris obstructing the fan.

Troubleshooting Tip: Listen for Unusual Sounds or Inspect the Blower

Listen for any grinding or squealing sounds from the furnace, which can indicate a blower motor problem. If the blower isn’t running, consult a professional HVAC contractor for installation of a new furnace in your home.

6. Furnace Safety Switch Preventing Heater from Turning On

The furnace safety switch prevents the system from overheating or running in unsafe conditions. If this switch is triggered due to overheating, a clogged vent, or an issue with airflow, the furnace won’t turn on as a safety precaution. This can help prevent potential hazards, but leave your home without heat until the issue is addressed.

Troubleshooting Tip: Inspect for Blockages and Reset the Safety Switch

Check your furnace’s vents and exhaust for any blockages or obstructions causing the system to overheat. After clearing any blockages, try resetting the safety switch. If the furnace still doesn’t turn on, contact an HVAC technician to inspect the system and offer repair services. 

7. Electrical Wiring Issues Causing Heater Malfunctions

Faulty or damaged electrical wiring can prevent your heater from turning on or cause intermittent operation. Wiring problems can result from wear and tear, rodent damage, or loose connections. These issues can disrupt the flow of electricity to the blower motor or control board, making it impossible for the heater to function.

Troubleshooting Tip: Inspect for Visible Wiring Issues

Inspect the wiring around your furnace for any obvious signs of damage, such as fraying or loose connections. However, electrical work can be dangerous, and it’s best to leave complex wiring repairs to a professional. If you suspect a wiring issue, contact an HVAC technician or licensed electrician to safely inspect and repair any faulty wiring.

Get Your Heater Back Up and Running with Superior Comfort Heating and Cooling

If your heater won’t turn on and basic troubleshooting hasn’t resolved the issue, it’s time to seek professional help. At Superior Comfort Heating and Cooling, we promptly address heating system issues to restore warmth to your home. 

At each service call, we start with a comprehensive inspection of your system to diagnose the exact cause of the problem. Once identified, we explain the issue clearly and provide an upfront estimate before beginning any repairs. Our HVAC technicians will work efficiently to resolve the issue, using top-quality tools and parts to ensure lasting results.

Call us today at (734) 929-9820 to schedule a consultation. 

FAQs

Why does my room get no heat?

If your room isn’t getting heat, it could be due to blocked vents, leaky ductwork, or an improperly set thermostat. Ensure vents are open and unobstructed, and check for any duct issues diverting warm air.

Why won’t my electric heater kick on?

An electric heater may not kick on if a circuit breaker is tripped, the thermostat is faulty, or an internal component fails. Check your breaker panel first, then ensure the thermostat is set correctly. If these don’t fix the issue, contact a professional to inspect the heater.

What causes heater failure?

Various issues, including dirty air filters, ignition system problems, thermostat malfunctions, or electrical faults, can cause heater failure. Regular maintenance helps prevent these problems by keeping the system in good working order.

How do I restart my heater?

To restart your heater, turn off the power at the breaker panel, wait for a few minutes, and then turn it back on. If it’s a gas heater, ensure the pilot light is lit. You may need to reset the thermostat or check for tripped breakers for an electric heater. If these steps don’t work, consult a professional.