
What you’ll pay for furnace repairs depends on many factors, including what parts are malfunctioning, where you live, and even the time of day. Here’s a breakdown of what can go wrong with your furnace and the cost to fix those issues.
Keep an eye (and an ear) out for these furnace issues
Clogged furnace filters are a common furnace problem in your home, causing inadequate heating and higher energy bills that need addressing every 30 to 90 days.
A faulty thermostat can shut off your furnace before finishing a heating cycle or prompt unnecessary operation when it struggles to read the temperature correctly.
Pilot light issues in your furnace show up as color changes or complete shutdowns, signaling dangerous carbon monoxide buildup or gas leaks that need immediate attention.
Hiring a local furnace repair professional provides trusted support with thermostat troubleshooting, relay switch replacement, and pilot light inspection, keeping your home safe and warm.
Whether it’s a sky-high energy bill or a screeching sound when you turn on your heat, there are some unpleasant indicators that you might have an issue with your furnace. While routine maintenance can prevent some furnace problems, others can occur no matter how well you take care of your heating system. Here are some of the most common ones you might encounter.
According to Angi data, nearly 41% of customers reported that their gas furnace or forced air heating system doesn’t provide heat or doesn’t get hot enough. Other common problems include pilot light out, makes odd noises, smells funny, and cycles off too rapidly or runs constantly.
There are a few situations in which a bad thermostat could cause furnace problems. For example, if your thermostat doesn’t maintain its settings, it could shut off the furnace before it finishes a heating cycle. Or, if the thermostat can’t read the temperature, it might prompt your furnace to turn on unnecessarily.
In some cases, you can identify and fix furnace thermostat issues yourself. Testing the batteries and removing any dust from the thermostat are two examples of DIY thermostat troubleshooting. If that doesn’t work (or if you notice any loose electrical wires), it’s better to call a professional.
Two repairmen arrived within 3 hours of my call, diagnosed the problem within 10 minutes (the temperature limiter inside the unit had failed, so it wouldn't allow the unit to heat), found a parts supplier close by, picked up the part, came back and replaced it, and had my unit working again within 2 hours.
— Elliott K., New York, New York
Over time, your furnace’s relay switch can corrode, overheat, or simply wear out. When this happens, the switch, which tells the motor to keep running, can get stuck or stop working properly.
If you think you might have a furnace relay switch problem, be sure to replace the part or contact a local furnace repair pro ASAP. The switch needs to work correctly. Otherwise, it puts your furnace at risk of electrical damage.

Dirty filters can cause a slew of furnace problems, including inadequate heating, poor indoor air quality, unnecessary stress on your HVAC system, and higher energy bills. Depending on your filter’s thickness, you’ll need to change it every 30 to 90 days. Fortunately, replacing a furnace filter is a simple task that you can tackle in about 15 minutes.
You could also run into furnace problems if your pilot light starts acting up. The flame should be blue (possibly with a yellow or red tip). If it isn’t, it could indicate that there’s too much carbon monoxide or that the pilot light is burning other substances (like dirt). Sometimes, the flame might even go out entirely. These situations can be dangerous, so we recommend hiring an HVAC professional to inspect any pilot light issues.
If your pilot light produces a strange smell that’s similar to rotten eggs, shut off the furnace immediately because there could be a gas leak. Then, leave your house and call emergency services.

However, not all types of furnaces have pilot lights. In fact, newer models often have electronic ignitions. If your furnace’s ignition quits working, you should bring in a pro to clean or replace it.
Like other parts of your furnace, the bearings on the blower motor can wear down as time goes on. When they need replacing before your furnace does, they’ll make a scraping sound. If you hear this, turn off the furnace and call an expert.
Similarly, if the blower motor’s belt frays or breaks, you might hear loud, high-pitched squeaks coming out of the furnace. Also, the belt sometimes slips out of alignment and needs readjustment. In either case, it’s best to have a professional fix it.
Heat exchangers, which warm up the air that goes through your ducts, can occasionally crack. If they do, you might feel unheated air coming through your vents, notice the pilot light changing colors, or hear a rattling sound coming from your furnace.
Hopefully you don’t have a cracked heat exchanger because it’s one of the priciest furnace problems to fix. But if you think you might, make sure to call a repair person ASAP. Otherwise, the damaged part could create a dangerous gas leak.

A furnace that runs constantly could signal a limit switch issue, which may lead to overheating within your HVAC system. If you’re experiencing this problem, have a furnace pro come check it out.
Of course, you don’t want your furnace to switch on and off all day, either. If it does, it might mean that your thermostat’s temperature is set too low or too high. Ideally, it should stay between 60 and 80 degrees Fahrenheit. If adjusting the temperature doesn’t help, try changing the filter.
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As usual with ECO, tech Jordan was outstanding, very professional, very knowledgeable, and very thorough with repairs made to tankless water heaters. Very highly recommend ECO!!!
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I would recommend this company to anyone! He showed up on time, was friendly, completed a very difficult repair on our dryer vent cover, was responsive, and pricing was extremely fair and competitive. I would have him back to do any of our repairs or cleanings without hesitation!
Ace Fireplace Services' chimney sweep service is truly exceptional. They used advanced technology to ensure a thorough cleaning process, and my chimney has never looked better. I highly recommend their services.
The technician was very professional and friendly. He answered all my questions and was very thorough. He left the fireplace area very clean . He inspected from the roof and advised me as to other work that might need to be done. There was no pressure there. I was very satisfied with the...
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On time, clean and finished fast. Windows seem sturdy and the finish is good. Caulking was done with no smudges. Would recommend.
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From average costs to expert advice, get all the answers you need to get your job done.

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