Imagine that it’s the middle of winter. Suddenly, your house goes from being toasty to becoming an icebox. After ruling out a power outage, you conclude that your furnace has stopped working. This guide will tell you what went wrong and how to fix it!
First, ensure that anyone you contact for repair is equipped and qualified to service your furnace. Some brands may require special treatment.
Second, many modern furnaces have an LED light that blinks red or green. Before you start repairing, write down what that LED light is doing. The light will blink in a code indicating the problem. Record this before turning the power off. For example, the LED may blink several times, pause, and blink again several times. Record the sequence and the number of blinks.
Let’s look at what could be going wrong and what you can do about the problem. Even if you call a repair service, a professional will appreciate the steps that you have already taken toward solving the problem.
Below are the five most common furnace problems and how to fix them if you want to DIY. Please remember to record the error code and turn your furnace off before attempting repairs. It is also important to understand that furnace parts can wear out and get dirty like anything else. This video by John Holland from All Utah Home Repair Services has a quick guide to basic furnace maintenance.
If your furnace turns on for about three seconds, then shuts off, you probably have a dirty flame sensor. This is the most common problem and one of the easiest to fix. The sensor will be located near the burners, usually opposite the ignitor. It is usually a metal rod. If this rod cannot sense the flame, it will shut the furnace off. Locating, inspecting, and cleaning the rod only requires a cleaning pad and basic tools.
Beware if your furnace restarts too many times; it will lock itself for three hours. Your furnace is not dead if this happens!
If your furnace turns on and off frequently, it may be time to replace your filter. Your furnace may also turn off because it doesn’t have adequate air circulation. The symptoms are similar to the dirty flame sensor problem, but the solution is different. Replace your furnace filter and repeat monthly or quarterly depending on conditions in the home.
If your furnace heats or cools your house at random or is turning on or off when unexpected, a broken thermostat is probably the culprit. The furnace has stopped regulating both your house and its internal heat. This problem could be as simple as a dead battery, or you may need to replace the thermostat.Often, a bad thermostat won't send a signal to the furnace at all, resulting in the unit not turning on at all.
If you turn your furnace on and nothing happens, the most likely issue is a faulty inducer motor. If you put your hand on the inducer motor and it feels hot, it is probably the problem. Your furnace may have a diagram for this part; please refer to that when trying to fix this part. The problem could be that something is stuck inside the motor’s blower wheel, or the motor has simply reached the end of its life. If you do need to replace it, the motor might cost $100–400, but installation services may raise that to $650.
If you smell burnt plastic, the problem is probably a bad blower motor. Your blower motor may also be hot to the touch. Unfortunately, the only way to fix a bad blower motor is to replace it. A standard blower motor may cost $600–700 to replace.
This is the epitome of “technical difficulties.” The only way to repair a faulty control board is to get a new one, which will cost around $300 to $650 and plenty of additional labor charges. Your furnace technician will replace it with one that matches the brand and model of your furnace.
If your furnace issue doesn’t match any of these, you can continue looking for your issue online or seek professional assistance.
If your problem goes beyond DIY, you may need to ask a professional. In many locations DIY repair work on furnaces is prohibited. LocalProBook will help you find the right repair person. A repair costs from $260–$2,500 depending on the damage. It’s important to weigh whatever quote you get against getting a new furnace entirely.
It is not recommended to attempt to repair a gas furnace on your own, as it can be dangerous and potentially lead to serious injury or damage to your home. Gas furnaces involve complex systems and components, and require specialized knowledge and tools to diagnose and repair issues safely and effectively.
Additionally, attempting to repair a gas furnace on your own can void the manufacturer's warranty and may not be covered by your homeowner's insurance in the event of damage or injury.
It's always best to leave gas furnace repairs to licensed HVAC professionals who have the training, experience, and equipment necessary to diagnose and repair issues safely and effectively. They can also ensure that the repair is done in compliance with local building codes and safety regulations.
If your furnace cannot be repaired, you must buy a new one. Including labor and installation, the average cost ranges from $3,000 to $7,600. The three most common brands are American Standard ($1,600–$6,000), Bryant (~$2,300), and Carrier (~$6,300).
Consider the following when buying a new furnace:
Size. The size of your house affects what size of furnace you will need.
Efficiency. Furnaces have gotten more efficient over time. If saving energy is a concern for you, it may be more expensive to buy a newer model, but it could also save you money over time.
Warranty. Your furnace should come with a warranty. Always read the fine print.
Air quality. If you have allergies or asthma, getting a furnace with good air filtration is critical.
Technology. A good user interface can help maintain your furnace without needing to call anybody immediately.
This video featuring Bryan of Fire & Ice Heating and Air Conditioning, Inc. in central Ohio covers most of the points that will help you decide if you should repair your current furnace or buy a new unit. A new furnace is a big investment that should serve you for years.
Alternatively, you may want to consider a heat pump. Although more expensive to install ($4,900–$12,000), heat pumps can save you money throughout the year and have no risk of gas leaks.
Carrier is a well-known and respected brand in the furnace industry, and they offer a wide range of furnace models to choose from. Here are three of the most popular Carrier furnace models:
Lennox is another well-known and respected brand in the furnace industry, and they offer a wide range of furnace models to choose from. Here are three of the most popular Lennox furnace models:
Trane is another popular brand in the furnace industry, and they offer a wide range of furnace models to choose from. Here are three of the most popular Trane furnace models and their estimated costs:
Please note that the actual cost of these models can vary depending on factors such as region, installation costs, and additional features or upgrades. It's always best to consult with a licensed HVAC professional for an accurate estimate.
Ultimately, the choice between a gas furnace and a heat pump depends on factors such as climate, fuel availability and cost, and personal preferences. It's best to consult with a licensed HVAC professional to determine which option is best for your specific needs and circumstances.
If you have a furnace issue, the first thing you should do is stay calm. The next thing is recording the brand and light pattern code. Then turn the furnace off so you can inspect it safely and decide if you want to attempt fixing it or call a professional. Even if you ask a professional instead of fixing the furnace yourself, they will appreciate your knowledge and initiative.