While you might not want to think about it, your furnace can experience a failure at any point in time. Being able to respond quickly to sudden furnace failures can make a world of difference in your home comfort. Below, we’ll address some of the most common reasons this will happen and what you can do about it.
How Your Furnace Works
Before we dive into the causes of sudden failures, it’s helpful to understand how your furnace normally functions. Gas and electric furnaces are the most popular types. Electric furnaces use a heating element to generate heat somewhat similar to a blow dryer. Gas furnaces burn natural gas or propane to heat the air that gets distributed throughout your ductwork.
All furnaces use a thermostat that serves as the brain of your system. The thermostat will signal to your furnace that it needs to heat your home. Your furnace will turn on its heating elements or activate its ignition components. Gas furnaces will have an electric igniter or a pilot light that will ignite the burner. The burner will have a steady supply of gas that it will burn to generate heat.
This heat travels through a heat exchanger. Heat radiates out on the exchanger housing and transfers into the air that passes by it. The toxic exhaust byproducts of the combustion process are safely vented to the outside of your home. The blower motor will start circulating the warm air that’s produced from your furnace throughout your ducting to warm your home.
Signs of Sudden Furnace Failure
A sudden furnace failure happens when there is an abrupt loss of heat or operation from your system without any warning. You may notice your furnace won’t turn on. It may short cycle, meaning it turns on and off repeatedly. Or, your air vents may not be producing warm air. Anytime your heating system is unable to produce a steady supply of hot air for your home, it’s considered an emergency. It’s important to diagnose the problem and repair it to maintain adequate home comfort.
Clogged Air Filter
One of the simplest reasons that your furnace may experience a sudden shutdown is due to a dirty or clogged air filter. The air filter is designed to capture debris before it can enter the internal components of your furnace. This is necessary to maintain the longevity of your furnace, and it’s great for boosting your indoor air quality level.
Unfortunately, as the filter gets clogged with debris, it can affect the performance of your heating system. The filter will act more like a wall that your heating system will struggle to pull air through. If there isn’t enough airflow in your ducting due to a dirty filter, your furnace’s heating elements or heat exchanger will start to overheat. This is simply because the heat it generates isn’t getting removed from that area.
All modern furnaces have built-in safety mechanisms that will shut off the furnace in the event of overheating. This is a safety requirement to prevent a potential fire in your system. If you have a dirty air filter that’s causing your furnace to shut off, you’ll notice short cycling. You’ll also notice only lukewarm air coming out of your vents when your unit is running.
Fortunately, this has a very easy fix you can do on your own. Simply turn your unit off and remove the old, clogged filter. Be sure to replace it with a filter of the exact same size. We recommend replacing the furnace filter every one to three months to prevent this issue from happening. It’s a good rule of thumb to check your filter once a month to stay on top of changes when necessary.
Thermostat Malfunction
Another reason you may experience a sudden furnace breakdown is due to a thermostat malfunction. If your thermostat screen is blank, it signals a problem with power. You can start by replacing the batteries in your thermostat to see if that regains power. If it doesn’t, check the circuit breaker to see if it has tripped and reset it if it has. If neither of these solutions works, it’s necessary to have one of our professionals evaluate the issue. In most cases, the issue lies with bad wiring or a faulty thermostat.
Ignition or Pilot Light Issues
For older furnaces to start, they need to have a pilot light. If this pilot light goes out, your furnace won’t be able to run. Fortunately, you can easily relight your pilot light with a barbecue lighter. Start by turning the gas valve off and letting your furnace sit for a couple of minutes. This will allow any excess gas to dissipate before you try to relight the burner for optimal safety.
Next, switch the gas valve to the pilot setting and hit the reset button as you use your lighter to ignite the pilot light. Be sure to hold the button for about 30 seconds to give your furnace enough time to heat up the thermocouple. Then, switch the gas valve back to the on position and ensure the pilot light stays lit.
If your furnace relies on an electric igniter, it can be helpful to check during operation to see if a spark comes from the igniter. If there’s no spark coming from the igniter, it could indicate a faulty igniter. If a spark does come from the igniter and lights your burner for only a few moments before the burner goes out, the issue likely lies with the flame sensor.
In some cases, the flame sensor can simply be cleaned off, while in others it will need to be replaced. It’s generally best to leave these furnace repairs up to a professional who can thoroughly evaluate the root cause of your faulty ignition and repair it swiftly.
Blower Compartment Malfunction
Another reason your furnace may stop suddenly is due to a malfunction in its blower compartment. In this scenario, you’ll notice that your furnace seems to turn on and run silently without the noise of the blower fan moving. When you check your air vents, there will be no airflow coming out of them.
Various components inside the blower compartment can fail. These include the motor, capacitor, control board, pulley, and fan belt. When any of these components fail, the blower won’t be able to circulate air throughout your home. It’s necessary to have one of our professional technicians further evaluate your blower compartment and determine the root cause of the issue.
Prevention
One of the best ways to greatly minimize your risk of experiencing a sudden furnace breakdown is to get routine maintenance service. This includes professional service every fall to prep your heating system for the upcoming season. This is great for detecting potential problems with your system and repairing them before you need to use it every day. Additionally, keeping up with routine filter changes will reduce the stress on your system and minimize your breakdown risk.
Reliable Furnace Repair Service
Gene’s Refrigeration Heating & Air Conditioning, Plumbing & Electrical offers reliable furnace repair service for the Medina, OH area. We can also assist with all your furnace replacement, repair, and maintenance needs. Call our friendly office staff today to book your next repair appointment.
