How to Troubleshoot 4 Common Furnace Problems

When the weather turns colder, many homeowners rely on their furnaces to keep them warm. However, furnaces can encounter various problems, mainly if they haven't been used in a while. While certain issues can be resolved with ease, others may necessitate the assistance of HVAC experts. In this blog post, we will explore some common furnace problems, including the following:

  • Your furnace is blowing cold air
  • Your furnace is making loud noises
  • Your furnace is failing to reach the desired temperature
  • Your thermostat is blank

Join us as we delve deeper into these issues and discover the most effective solutions.


Is your furnace experiencing problems?

At Four Seasons Heating & Air Conditioning, we offer a team of expert heating specialists with years of experience diagnosing and resolving common furnace issues. For high-quality furnace repairs at fair prices, call us at 503-538-1950 or request an appointment online today. Book with us to see why we have over a thousand 5-star reviews from your fellow Portland homeowners.

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Your Furnace Is Blowing Cold Air

When your furnace blows cold air, the most straightforward explanation could be an incorrectly set thermostat. The thermostat plays a crucial role in instructing your furnace to reach the desired temperature. Besides accidentally setting the temperature too low, there are two other possibilities you should consider ruling out.

Firstly, check if the thermostat is set to cool. This setting takes your furnace offline and activates the air conditioner instead. If this setting is mistakenly changed, cool air flows through your vents instead of heat.

Secondly, ensure that the thermostat fan is set to AUTO. This allows the thermostat to shut down properly between heating cycles. When the fan control is in the ON position, it continuously blows air even when the system is not generating heat. This leads to cooler air circulating throughout your home, reducing the interior temperature and causing your furnace to work harder to maintain your comfort.

Lastly, power your furnace off and then power it back on. If you have verified that these settings are correct and your furnace is still blowing cold air, it's time to seek assistance from Four Seasons Heating and Cooling.

Your Furnace Is Making Loud Noises

When your furnace starts making a loud noise, it's a clear sign that something's up with your system, and you'll probably need a technician to take a look at it.

To figure out what's causing the noise, it's important to identify the specific type of noise it's making. Homeowners often complain about three types of furnace noises: whistling, rattling, and banging.

Now, let's talk about that whistling noise. One possible reason for it is a clogged air filter. See, the air filter's job in your HVAC system is to trap dust and debris so they don't circulate in your home's air. But if you forget to change the filter for a while, it can get all clogged up, blocking the airflow. That's when you might hear a whistling noise as the air struggles to squeeze through the congested filter and make its way into the return duct.

By swapping out the clogged air filter, you'll get the airflow back on track and bid farewell to that annoying loud noise.

Your Furnace Is Failing To Reach the Desired Temperature

If your furnace is failing to reach the desired temperature, there could be several reasons behind this issue:

  • Thermostat troubles: Make sure your thermostat is set to the temperature you want and switched to "heat" mode. Don't forget to double-check any programmable settings you've got going on.
  • Blocked or closed vents: Inspect all the vents throughout your home to ensure they are open and unobstructed. Blocked or closed vents can restrict the airflow and hinder the furnace's ability to distribute warm air effectively.
  • Dirty air filter: A dirty air filter can impede airflow and reduce the efficiency of your furnace. Check the air filter and replace it if it appears dirty or clogged. Regularly replacing the air filter is essential for optimal furnace performance.
  • Ductwork issues: Examine the ductwork for leaks, gaps, or blockages. Damaged or poorly insulated ducts can result in heat loss, making it challenging for your furnace to reach and maintain the desired temperature.
  • Insufficient insulation: Inadequate insulation in your home can lead to heat loss, making it harder for your furnace to achieve the desired temperature. Check windows, doors, and walls for any gaps or areas lacking insulation. Adding insulation or sealing gaps can help retain heat and improve furnace efficiency.
  • Aging or malfunctioning furnace: If your furnace is old or experiencing mechanical issues, it may struggle to reach the desired temperature. Reduced efficiency or component malfunctions can hinder its performance. In such cases, it's best to consult a professional HVAC technician to assess the furnace and recommend appropriate repairs or replacements.

Remember, every furnace issue is unique, so if you're stumped or the problem won't quit, don't hesitate to bring in the professionals. They've got the know-how to get your furnace firing on all cylinders again!

Your Thermostat Is Blank

If your thermostat is blank and showing no display, there are a few potential reasons behind this issue:

  • Power supply: Check if the thermostat has power. Ensure that it is properly connected to a power source or that the batteries, if applicable, are not dead. Sometimes, a blank display simply means there is no power reaching the thermostat.
  • Tripped circuit breaker or blown fuse: Verify if the circuit breaker or fuse connected to your HVAC system is functioning correctly. If it has tripped or blown, it can result in a loss of power to the thermostat, causing it to go blank.
  • Loose wiring or faulty connections: Inspect the wiring connections between the thermostat and your HVAC system. Loose or disconnected wires can disrupt the power supply and cause the thermostat display to be blank. Ensure that all connections are secure and in good condition.
  • Malfunctioning thermostat: It's possible that the thermostat itself is faulty or experiencing a malfunction. Over time, thermostats can wear out or encounter internal issues that result in a blank display. In such cases, replacing the thermostat may be necessary to restore functionality.

If you've checked the power supply, circuit breaker, and wiring connections, and the thermostat display is still blank, it's advisable to consult a professional HVAC technician. They have the expertise to diagnose the problem accurately and recommend appropriate solutions to get your thermostat up and running again.


Contact Our Heating Experts Today

Four Seasons HVAC technicians in branded t-shirts standing in front of service vehicles parked in front of their warehouse

Whether your furnace is overheating, short cycling, or simply refusing to turn on, the experts at Four Seasons Heating & Air Conditioning can help. Since 1979, we've assisted Portland homeowners with reliable furnace repairs, convenient scheduling, and honest prices.

Enjoy good, old-fashioned 5-star service with a 100% satisfaction rate by calling us at 503-538-1950 or requesting an appointment online today.

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