Why Won't My Furnace Shut Off?

Whether it’s a mild winter in Phoenix or you’re experiencing arctic temperatures, a working furnace can be a lifesaver. However, a furnace that won’t turn off can be a major issue in the most inconvenient times. Your Phoenix furnace should have natural cycles where it turns on and off. A furnace that won’t shut off can be costly and damaging. Learn some common issues that you can fix, as well as other issues that require professional help with this comprehensive guide.

Identify the Issue

There are many signs that indicate your furnace isn’t working properly, but a common problem is a furnace that continues to run. Take a look at these five common problems, and learn what you can do to fix them:

  1. Wrong thermostat setting
  2. Old air filter
  3. Damaged thermostat
  4. Damaged blower motor
  5. Ductwork that leaks

We’ll take you step-by-step through each issue to find the right solution for your home. If the solution is manageable on your own, your furnace will be working properly again in no time. Otherwise, our professional team at Day & Night Air can fix your furnace with friendly and prompt service.

Proper Furnace Maintenance

Before any of these issues arise, or after they’ve been successfully fixed, proper Phoenix furnace maintenance can help you avoid costly repairs in the future. Some furnace maintenance can be complicated, but there are some basic tips you can do on your own.

Keep your thermostat adjusted correctly. During summer, you may want to keep your home slightly warmer in order to save on energy costs. However, during the winter, you may want to adjust the temperature lower. This allows you to not only save money on your heating bill, but also helps keep your furnace running longer. An overworked furnace won’t last as long as a furnace set at an efficient temperature. Here is a list of things to check to try to uncover the issue you are facing with your furnace:

Step 1: Check the Thermostat

If your furnace won’t turn off, the easiest issue to fix is your thermostat. There are two basic ways you can adjust your thermostat to ensure it isn’t what’s keeping your blower running. First, your temperature may be set too high. A furnace that is working hard to keep a high temperature, especially when it’s extra cold outside, can seem to run continuously.

The second common thermostat problem is the fan switch. Your fan can be adjusted manually from your thermostat. Many thermostats have two settings: AUTO and ON. Other thermostats also have an OFF selection. Make sure your fan switch isn’t turned to the ON setting. This keeps your fan running constantly, even if the furnace isn’t producing hot air. If your blower is still running even after the temperature and fan switch have been adjusted, it’s time to go to your furnace and check out the air filter.

Step 2: Check the Air Filter

When was the last time you changed your air filter? A clogged air filter can dramatically decrease the air flow of your entire system. This can cause your furnace to run far longer, even continuously.

There are many factors that can determine when to change an air filter. Here are just a few things to consider that may require you to change your filter more frequently than typical:

  • Pets
  • An unusually dusty home
  • Smoking
  • Keeping doors and windows open often
  • Filter size
  • The length of time the blower is on

Filters are generally changed every three months, but these factors can increase or decrease that time. Some filters can last up to 12 months, while others should be replaced monthly. Ask a professional about your particular furnace and home situation to determine the ideal frequency for you.

To replace a furnace filter, simply locate the filter, remove the old filter, and replace with a new one. Be sure to choose the exact size of your old filter, which should have the measurements printed clearly on the side. If your filter has a plastic frame, it may be a reusable model that simply needs to be rinsed and air-dried. Homes that require frequent filter replacements should consider investing in a reusable filter. You’ll still need to clean the filter frequently, but this can be a great investment if you need to replace your filter often.

After replacing your filter, you should notice a significant difference in the sound and volume of airflow. If not, consider contacting a professional to determine the next step.

Issues That Require Professional Help

Professional heating and air service companies, such as Day & Night Air in Phoenix can promptly diagnose and fix any furnace issue. If your furnace won’t shut off after adjusting the thermostat and replacing the air filter, it’s time to call a heating repair service. At Day & Night Air, our dedicated service team works around the clock. Any time of day, any day of the year you can set an appointment for service with a trained Phoenix technician who can help you fix your furnace and get warm air quickly.

Based in Phoenix, Arizona, our technicians are able to deal with local problems and find effective solutions. Here are just a few common issues that require professional services.

Heating Repair Phoenix

Issue 1: Thermostat Malfunction

A thermostat is a complicated system that sends signals to your furnace and blower depending on the temperature it detects in the room. Some thermostat malfunctions are caused by faulty wiring. Wiring issues require experience with electricity, so it’s not a good idea to attempt to repair a thermostat on your own.

Whether you need a new thermostat, new part, or just wires that need to be reconnected, a professional HVAC technician can quickly solve this issue. Even if your furnace begins turning on and off correctly, you may want to consider replacing your thermostat if you feel the temperature isn’t accurate or consistent.

Issue 2: Damaged Blower Motor

The blower is the part of your HVAC system that forces both hot and cold air throughout your home. If you have a central air conditioner, this system will also use your blower. An air blower has many complicated parts that can need to be repaired or replaced.

A blower that won’t turn on is more frequently associated with a damaged blower motor, but some issues can cause the motor to stay running. Either way, this system requires extensive knowledge of the electrical and mechanical components of an HVAC system. DIY repairs can cause more damage to your system and working with electricity around natural gas or propane can be dangerous. Contact an expert at Day & Night Air to easily repair or replace your blower motor. We can discuss the problem in depth, and help you identify the most cost-effective solution for your home.

Issue 3: Ductwork Leaks

Ductwork is the metal system that is used to force air throughout your home. Whether you’re circulating cool air in the summer or warm air in the winter, ductwork is an essential part of your HVAC system that allows for even distribution of air.

Leaky ductwork is inefficient. With too many leaks in your ductwork, your home may not be circulating air effectively. If you notice uneven temperatures in your home, particularly if the room with your thermostat is cooler than other areas of your home, then the thermostat may not be reaching adequate temperatures to turn your furnace off.

Sealing ductwork can be time-consuming, particularly if you’re unsure of the exact location of the leak. You’ll also want to seal any leaks in your crawl space or attic, which can be a difficult job for many homeowners. Our expert HVAC technicians can diagnose any issues with your ductwork and quickly seal your ductwork.

Leaky, uninsulated ductwork can not only keep your furnace running, but it’s also inefficient. Even if your furnace shuts off, consider calling our team to keep your furnace running efficiently.

Replacing Your Furnace

If your heating won’t turn off, your furnace probably doesn’t need to be replaced. As long as the blower is still forcing warm air, your issue should be handled easily with a replacement part. However, some issues can be more serious, particularly if your furnace won’t turn on.

Discuss the health of your furnace with our Phoenix HVAC specialists. Replacing a furnace can be a costly decision, so you want to know as early as possible when your furnace may need to be replaced.

One particular issue that may require your furnace to be replaced is the size of your unit. If a furnace is too small, it may be overworked trying to heat your entire home. This is particularly common in a home that has recently been renovated or had an addition. If you’re attempting to heat a significantly larger space, you may need to consider a furnace upgrade.

A furnace is sized based on the BTUs it produces, so it can be difficult to find the exact model you need. An HVAC technician can perform accurate estimates to discover the ideal size furnace for your home and climate.

Contact Day & Night Air Today

If your furnace won’t shut off, don’t wait and suffer in a cold home. Contact us today to schedule a service appointment in Phoenix. Whether it’s the middle of the night, weekend, or a holiday, you’ll always enjoy prompt service from our team. Choose the best service in your area that offers comprehensive diagnostics, convenient scheduling, and local HVAC experts. We serve areas all across the state, including

  • Phoenix
  • Apache Junction
  • Fountain Hills
  • Arcadia
  • Cave Creek
  • Mesa
  • Tempe
  • And more

Whether you’re able to fix your furnace issue or not, our friendly technicians would be happy to assist you in learning more about your furnace. Discover how to properly maintain your furnace, and receive fast repairs and replacement parts with Day & Night Air. Running a furnace in Arizona in the winter can be expensive enough; don’t let a furnace that won’t shut off cost you even more on your next energy bill.