Furnaces continue to be the most popular way to heat homes in the U.S. They are efficient and deliver substantial, quick and consistent heat. Furnaces do require maintenance and can sometimes develop issues that demand immediate attention. Let’s explore the signs that your furnace needs servicing.
1. Carbon Monoxide Alert
All furnaces that burn fuel, such as natural gas, heating oil and propane, produce carbon monoxide (CO) as a byproduct. In a well-functioning system, those flue gases exit your home via a flue pipe. Heat exchangers can rust over time. That makes them brittle and susceptible to cracking. Cracks allow the flue gases to leak into the air you breathe. Seasonal maintenance is important for all furnaces but particularly the fuel-burning kind for this reason. This is also why experts recommend CO detectors in the home. If you get a CO alert, turn the furnace off. Don’t turn it back on before having it serviced.
2. Pilot Light Color Other Than Blue
Pilot lights burn blue because methane emits a blue glow when ignited. If a furnace pilot light burns another color, such as orange, red or green, there is a combustion problem. A technician may need to adjust the pressure of the fuel supply. The furnace could have a clogged air intake valve. There can also be dust, rust flakes or other impurities burning alongside the fuel. In any case, stop using the furnace until you’ve had a professional fix the issue.
3. Can’t Relight Pilot
A pilot light can go out from time to time. A common cause is a buildup in the intake valve, which restricts the amount of oxygen. In most cases, you can relight the pilot without issue. If it goes out again, you shouldn’t continue relighting it. Call a professional instead. There could be more serious airflow issues or a blockage in the pilot tube preventing the fuel from getting through. The thermocouple may require cleaning, or it may be malfunctioning and need to be replaced.
4. Increased Energy Consumption
You should track the energy consumption related to your furnace month to month and year to year. This way, you’ll know when energy usage is abnormal. Spikes in energy use are often the first sign of a furnace problem. It’s important to note that with fuel-burning furnaces, you can expect a gradual efficiency loss of about 1% a year. Sharper losses indicate a dirty furnace or a failing component. Decline happens with electric furnaces, too, but not as sharply as with fuel systems. That said, when a spike occurs with electric units, the increase may be much higher than what you’d experience with fuel.
5. Weak or Cool Airflow From Vents
The temperature of the air coming out of your vents should be between 120 and 140 degrees Fahrenheit. You should be able to feel the air as it flows out, and it should feel hot. The vents should not, which indicates a venting problem. If the air feels weak or cool, you have an issue. There is a wide range of causes, including a bad or incorrectly set thermostat, clogged air filter or combustion problem.
6. Uneven Heating
Airflow issues can eventually manifest in your home in other ways. You may experience cold spots in rooms. An entire room can feel cooler or warmer than others. In multistory houses, you can experience a temperature difference of 2 degrees or more between levels. Potential causes are similar to the reasons airflow may be cool or weak. Other possible reasons include a blower operating at too low a speed or air leakage in the ducts.
7. Short Cycling
Cycling refers to how often and long a furnace runs. This will vary based on the furnace model and capacity and size of the home. The typical furnace will run two to three times an hour and for about 10 to 15 minutes. Short cycling is when a furnace runs more frequently than that. A new furnace short cycling suggests an undersized or oversized unit. If it happens suddenly, a clogged HVAC filter is a common cause. If you have a thermostat that runs on battery power only, check for dying batteries. It could also be an issue with the blower causing the furnace to turn on and off.
8. Long Cycling
Long cycling is when a furnace runs for too long. Typically, the home will not feel as warm as usual. The temperature in the home isn’t reaching your setting and so the thermostat keeps the system running. A clogged air filter is a common cause. An open blower door is another. You can also inadvertently cause this problem by closing off vents. If you have a high-efficiency furnace, they create water as a byproduct. In that case, the problem can be a clog in the condensate drain line.
9. Unusual Noises
Odd noises will often accompany faulty furnace operation, and the type of the sound often indicates the nature of the problem. Squealing or screeching suggests an issue with the blower motor or belt. In fuel-burning systems, booming or banging may point to a buildup of gas or a problem with the ignition. Rattling or vibrating is a sign of a loose component or debris in the system.
Whistling suggests a clogged filter or other airflow obstruction. Clicking with a failure to engage means that there’s a loose wire or a faulty switch or that the blower has failed. Hissing noises often indicate either an air or a gas leak. Other potentially problematic noises include grinding, popping and scraping.
10. Unpleasant Smells
Furnaces may create a smell when turning on that fades shortly after. This is usually dust burning and suggests you need to have your furnace cleaned. If the smell is musty, it can indicate mold, a humidifier filter that needs changing or a clogged drain line. If you have a fuel-burning system, the rotten egg smell may mean that you have a leak. Disable the system, and call in the pros.
11. Excessive Soot
Regular maintenance will help prevent soot buildup in fuel-burning furnaces. If you see soot building up despite this, it suggests a problem. It could be inefficient burning or a cracked heat exchanger. This is a serious problem as it may be a precursor to CO in the air.
12. Visible Corrosion
Any sign of rust or other corrosion is a serious problem as well and demands a professional inspection. It can happen over time because of the combustion process. Corrosion can also indicate a humidity problem in the area where your furnace is located.
Do You Need a Furnace Repair?
We Care Plumbing, Heating and Air has served Southern California for over 20 years. We have offices in Murrieta, Orange, San Marcos and Temecula. Our technicians repair furnaces in addition to heat pumps, air conditioners and ductless mini-splits. We install and maintain those systems as well. Our indoor air quality services include duct cleaning, air purification and humidity control.
We have a plumbing team, too. Our plumbers perform inspections, maintenance, repairs, installations and repiping. We specialize in fixtures, tank and tankless water heaters, water treatment systems, garbage disposals, sump pumps, septic systems and sewer lines. Schedule your furnace repair appointment online or by phone, or contact us with any questions. It’s a good idea to schedule maintenance for your heating system before the start of the season, too!
