10 Reasons Your Heat Won’t Turn On

Nov 23, 2020

10 Reasons Your Heat Won’t Turn On

It’s always so difficult when your heater wont turn on, as you count on your heater to function properly to keep all your living spaces warm and comfortable. But what happens when you adjust the thermostat and the heat doesn’t turn on?  What is preventing your furnace from working the way it should? If your central heating is not operating correctly, there are many reasons why. Here are some of those reasons: 

  •   Thermostat

When the heater doesn’t turn on, the first thing you should check is the thermostat. Make sure the power is turned on and check your circuit board to be sure the unit is receiving power. Then double-check to be sure the furnace door is completely shut. There could also be a switch inside the door that shuts off power to the unit if the door isn’t correctly shut.  If you have a battery-operated thermostat, you can just change the batteries. If your unit has fuses, be sure the fuses are not burnt out. 

  •  Lack of Maintenance

More often than not, the problem here is the furnace is dirty, which would be discovered during routine maintenance.  When you have a dirty filter it can bring about equipment failure. The heat exchanger will not operate correctly if there is not sufficient cool air that moves into it, preventing it from overheating. When the motor is dirty, the heat exchanger is not exposed to enough moving air. So then it just malfunctions.  What’s more, dirty air filters limit airflow and can magnify existing problems with improper duct sizing.  It is recommended you change your air filters every three months.  A dirty flame sensor prevents your system from lighting the burners. The flame sensor won’t “sense” the flame, so it will cut off as soon as it turns on. The less frequently you clean your system, the more likely you are to cover your flame sensor with a dense layer of gunk.  Dirty burners also make it difficult for your furnace to function properly. The solution is to have a field service technician from Apollo Heating and Air Conditioning clean your system annually. Regular maintenance has many advantages that include avoiding the inconvenience and discomfort of a non-functioning furnace and being able to detect potential problems with your equipment. 

  •  Ignitor or Pilot Light

If you own a gas heater, be sure the pilot light is lit. If the thermostat has power and is functioning, but the heat does not come on, shut off the gas reset valve located inside the unit. Then, wait for about five minutes and turn the unit on again.  It is important to make sure the unit has gas. If it does, and the ignitor is not working, you should call Apollo Heating and Air Conditioning to resolve the problem. 

  •  Too Much Gas

More often than not, furnace manufacturers provide specs that tell you how much gas their equipment should burn. You have to adjust the equipment during the installation process to ensure it works correctly. If not, it could stop working at a very inconvenient time – as in during harsh winter weather.  Occasionally, improperly calibrated furnaces burn too much gas. When that occurs over a long enough time period, two things can happen: 

  1. You pay too much for energy usage during the winter
  2. The furnace overheats, causing it to cycle on a limit switch

At Apollo Heating and Air Conditioning, we always perform a combustion analysis during our yearly furnace inspections, which lets us know if your furnace is burning too much gas. 

  •  Dead Blower Capacitor

Your blower capacitor typically looks like a big battery. The capacitor is responsible for starting your furnace after the thermostat setting tells it to turn on.  Capacitors are equipped with tolerance levels. For example, if the tolerance is below a certain level, your blower might not reach the proper RPM.  In some cases, the capacitor will not start the blower. A very unfortunate scenario is when a dying capacitor leads to a blower malfunction, and that is very costly to repair.  Apollo will check the tolerance of your capacitor (s) during routine inspections. 

  •  Low Refrigerant Levels

If you heat your home with a heat pump, your refrigerant level could get to be too low, and that leads to your heat strips coming on more often than they should. This can be a costly problem as it typically leads to exorbitant utility bills.  All you need to do to avoid this problem is to recharge the refrigerant – and fix leaks – so you can avoid replacing your compressor. Another option is replacing the system with a new one that uses a newer, R-410A refrigerant. 

  •  Dead Starting Components (Heat Pump)

Failed starting components can prevent your blower (indoor unit) or outdoor unit from starting correctly. As a result, your system will not heat your home, and you’ll need to replace the bad parts.  Regular maintenance and frequent inspections can help you detect problems with these components before they go bad. You’ll also prevent costly repairs down the line. 

  •  Bad Inducer Draft Motor

Known also as a “draft inducer,” this small motor clears the heat exchanger of leftover gas from a prior cycle and vents all gases generated during the furnace’s combustion process.    If the inducer motor starts pulling high amps, it can slowly burn out. When it gets dirty, that causes safety switches to cut the furnace off entirely. 

  •  Cracked Heat Exchanger

A cracked heat exchanger can lead to the following scenarios: 

  • It will impact the efficiency of your energy system. 
  • Cracked heat exchangers are occasionally indicative of another issue that might cause your furnace to fail, such as low airflow due to dirty components.  

This is a dangerous problem to have, so, if you have a cracked heat exchanger, you need to replace it right away. Why?  Heat exchangers contain carbon monoxide (CO). When they crack, the CO escapes. CO has the potential to make you sick and it can be fatal in serious cases. 

  •  Improper Ductwork Design and/or Installation

Proper ductwork design and installation is a big job. Some builders and HVAC contractors cut corners or rely on rules of thumb – instead of building science – when sizing and installing ducts. When there is poor design and installation, you will never have proper airflow throughout your home, making you uncomfortable. What’s more, your furnace will short cycle more frequently.  The solution is to contact Apollo Heating and Air Conditioning and have us fix the failed HVAC components and redesign your ductwork.   

Keep Your Furnace in Optimal Condition by Looking to Apollo Heating and Air Conditioning for Expert Service

A quality furnace system is one of the most important investments you can make in your home. The system adds both value and comfort to your living space and should be regularly maintained to keep it in top working order.  Look to the HVAC experts at Apollo Heating and Air Conditioning to ensure your energy system is in excellent condition.   At Apollo Heating and Air Conditioning, we are committed to delivering premium quality HVAC service, maintenance, products, and documentation in Kennewick, Pasco, Richland, and beyond!  Learn more by contacting Apollo Heating and Air Conditioning! Call us at (509) 396-COLD (2653).