Fix 7 Common HVAC Problems With These Furnace Troubleshooting Tips
Get your furnace firing and turn up the heat
Here’s a scenario you never want to find yourself in: It’s the middle of winter, and your furnace just stopped working. It can be nerve-wracking, but luckily, there are several ways to handle common furnace problems on your own—without calling for professional help. Before you hire an HVAC expert, try these seven DIY furnace troubleshooting tips.
1. Change Your Furnace Filter
Keeping your filter clean and debris-free is one of the easiest ways to extend the life of your heating system. Why? When your filter is blocked by dirt, dust, and hair, your furnace has to work harder (and use more energy) to heat your home, which puts extra stress on the entire HVAC system.
On top of that, a dirty air filter can reduce airflow around your home, negatively impacting your indoor air quality. In some cases, a dirty filter can force your furnace to overheat or shut off on its own.
Most filters should be changed every three months, but this may vary depending on your filter type and thickness. Not sure if it’s time for a filter change? Turn off your furnace, pull out the filter, and inspect it. If it looks dirty, swap it out for a new one as soon as possible.
2. Inspect Your Circuit Breakers
Checking your circuit breakers is another quick idea for troubleshooting your furnace problems. If certain appliances in your home are using too much power at once, it could create a circuit overload and trip your breakers. Here’s how to fix it.
At the circuit breaker box, find the switch that controls your furnace. If your circuit breaker tripped, the switch will be between the “on” and “off” positions. You can reset it by turning it off completely and then flipping it on again.
3. Check Your AC Wires
Can’t get your furnace to start? It could be a wire issue. To find out, head to your AC unit and look for any wires that are dangling or look out of place. If you’re comfortable working with electric systems, you can try reconnecting any disconnected wires yourself. Otherwise, this would be a good time to call in a local furnace repair person to identify and fix the problem.
4. Swap Out Your Thermostat Batteries
Dead or dying thermostat batteries are another potential reason that your furnace isn’t working. Typically, battery-powered thermostats will have an indicator that tells you when to replace the batteries. If yours is flashing, inserting a fresh set of batteries could solve the problem.
5. Look for an Error Code
Many newer furnaces have a feature that indicates when something isn’t right—usually in the form of flashing lights. For example, some furnaces will have a solid green light if everything is working properly. But if the light starts blinking or changing colors, it can indicate a specific problem, like an issue with the ignition or gas flow.
Not sure what a particular code means? Check inside your furnace’s access panels. There may be a guide that explains each signal.
6. Examine Your Gas Valve
A gas valve is an important part of your furnace that controls the flow of gas into the system. When you’re running your furnace, the valve should stay in the “on” position.
To find your gas valve, look for the gas line that runs into your furnace. The valve will be near this line and should have three settings: on, off, and pilot.
7. Relight Your Pilot Light
If you have an older furnace, it should have a pilot light that stays lit and ignites the burners to heat your home. Occasionally, the pilot light might go out and prevent your furnace from working correctly. In that case, you may need to relight the pilot light.
Start by turning off the gas valve, then wait five to 10 minutes for the gas to dissipate. Then, turn the knob to “pilot” and reignite the pilot light with a long lighter or match while pressing the “reset” button. It should remain lit, allowing you to turn the knob back to “on.”
When to Hire a Pro for Furnace Troubleshooting
While it’s good to understand how to troubleshoot furnace issues, you might run into some HVAC problems that you can’t fix on your own. If your furnace still isn’t working after trying these suggestions, it’s time to call in an expert.
So, how much does it cost to hire a professional to fix your furnace? It depends on a few factors, including the severity of the problem, the type of furnace you have, and where you live. In general, though, most furnace repairs cost between $130 and $500. But if you have major damage and need a replacement unit, a new furnace costs anywhere from $2,820 to $6,810.
Lydia Schapiro contributed to this piece.
Frequently Asked Questions
There are several ways to fix a furnace that is not heating, depending on what’s causing the problem. For example, a clogged filter could prevent your HVAC system from pushing heat through your home. In that case, you could replace the old filter with a new one. However, some problems are more complex and are best handled by an expert.
Some of the most common furnace problems involve extinguished pilot lights, faulty thermostats, dirty filters, and tripped circuit breakers. If you’re dealing with any of these issues, you can try to fix them on your own. But if your furnace is showing signs of a more serious problem—like making odd noises or running continuously—it’s best to contact a professional.
The typical life span of a furnace varies, depending on which type you have. For instance, gas furnaces usually last between 15 and 20 years, but some can last for 30 years or more. Electric furnaces have life expectancies of 20 to 30 years, while oil furnaces last for around 15 to 20 years, with some working for up to 25 years.
Furnace coils are some of the most expensive parts to replace, costing between $600 to $2,000 or more. Heat exchangers are also pricey, with an average price of $500 to $1,500. Other expensive-to-replace parts include draft inducer motors, which cost $200 to $1,500, and blower motors, which can run up to $2,000.