Your furnace will blow cold air if there is no air to heat and send back into your home. Another reason you may not be getting enough air flow is if your ductwork is not sized properly. Unfortunately,this is quite common. If your return ductwork is too small, it will not be able to take in the required amount of air.

Should I turn my furnace off if its blowing cold air?

When a furnace only blows cold air, there’s a chance the heater could have overheated. But don’t worry, this usually doesn’t mean the unit is broken. When the system overheats, there’s a safety feature that shuts the system off. This is a good thing—it could prevent a fire, carbon monoxide leak, or even an explosion.

How do you reset a furnace that blows cold air?





Pilot Light Is Out

  1. Turn off power to the furnace.
  2. Locate the pilot light assembly and turn the reset switch to OFF.
  3. Wait 10 to 15 minutes to allow any escaped gas to clear the area.
  4. Turn the reset switch to PILOT. …
  5. Once the pilot is lit, turn the switch to ON.
  6. Restore power to the furnace.

Why is cool air coming from the vents even though heat is on?

This issue could be caused by an improper thermostat setting. Check that the fan blower switch is set to “auto” and not “on.” When the “auto” setting is chosen, the fan will only run during a heating cycle and won’t push air that feels cooler through the vents in between cycles.

Why is my heat not working at night?

Short-cycling: If you notice the furnace shuts off regularly at night, it may be short-cycling. This happens when the furnace is too large for your home. If your furnace is short-cycling, it will turn on for a short period, then turn right off. This prevents it from heating your home properly.

Why is my furnace blowing cold air sometimes?





There are several different reasons your furnace may be blowing cold air. A furnace that blows cold air could be a result of an improper thermostat setting, a dirty air filter, a faulty fan limit switch, or something else entirely.

Can a dirty furnace filter cause no heat?

A clogged furnace air filter will negatively affect the airflow throughout your house and HVAC system. The lack of fresh air in your furnace will cause the heat exchanger to become too warm and deactivate. Dirty filters indirectly cause short cycling issues and will make it hard to keep your home warm.

How do I know if my furnace air filter is dirty?

What Are the Symptoms of a Dirty Air Filter?

  1. Filter is a different color. …
  2. Energy bills are higher than usual. …
  3. Low air flow. …
  4. Rise in physical issues. …
  5. Headaches. …
  6. Allergies. …
  7. Carbon monoxide poisoning. …
  8. Forces HVAC systems to work harder.

What are the signs of a dirty air filter?

8 Dirty Air Filter Symptoms: How to Know When to Clean Your Air…

  • Air Filter Appears Dirty. …
  • Decreasing Gas Mileage. …
  • Your Engine Misses or Misfires. …
  • Strange Engine Noises. …
  • Check Engine Light Comes On. …
  • Reduction in Horsepower. …
  • Flames or Black Smoke from Exhaust Pipe. …
  • Strong Fuel Smell.


How often should furnace filters be changed?

The 90-day recommendation is for 1- and 2-inch filters. If you have a thicker model, the filter life extends. For 3- and 4-inch filters, plan for a replacement about every six to nine months. If you have the larger 5- or 6-inch filters, they will need replacing every nine to 12 months.

Where is furnace filter located?

Your furnace filter will most likely be found in the blower of your furnace. Where the blower is depends on how the furnace was installed. Horizontal HVAC unit – Furnace filter will be located on the intake side, slid into a rack.

Can I run my furnace without a filter?



If you were to use your home furnace without an air filter, all that dust and debris could get stuck in your system and cause a rather large buildup. Over time, these buildups can clog and damage your system. To protect and extend the lifetime of your system, we recommend only running your furnace with an air filter.

How long do furnaces usually last?

15 to 20 years

A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.

How do you know if your furnace is dying?

Aging furnaces often make some strange noises toward the end of their life — banging, popping, rattling, or squealing. Or you may you hear the furnace blower running excessively, turning off and on frequently, or blowing cold air sometimes. These may mean your furnace needs to be replaced.

How do I know if my furnace needs to be replaced?



8 Telltale Signs Its Time to Replace Your Furnace

  1. The Age of Your System. …
  2. Rising Energy Bills. …
  3. Excessive Dust, Dirt, Soot or Rust Particles. …
  4. Home Humidity Problems. …
  5. Rooms are Heating Unevenly. …
  6. Furnace Becomes Unusually Noisy or Develops Rattles, Buzzes or Hums. …
  7. Furnace Has Visible Signs of Rust or Cracks in or Around System.

How much is a new furnace for a 2000 square foot home?

The average cost range for purchasing and installing a gas furnace designed to heat a 2,000-square-foot home with a 97% efficiency rating ranges from $4,000 to $8,000, with most homeowners spending around $6,000 total on a high-efficiency gas furnace replacement in a 2,000 sq. ft.

What is the most reliable furnace brand?

Best Furnace Brands

  • American Standard Furnaces.
  • Amana Gas Furnaces.
  • Bryant Furnaces.
  • Carrier Furnace Units.
  • Daikin Furnaces.
  • Goodman Gas Furnaces.
  • Lennox Furnace Units.
  • Rheem Furnaces.

What size furnace is needed for a 1500 square foot house?

between 45,000 to 90,000 BTUs



A 1,500-square-foot home will require between 45,000 to 90,000 BTUs. A 1,800-square-foot home will require between 55,000 to 110,000 BTUs. A 2,100-square-foot home will require between 65,000 to 125,000 BTUs.

Should I replace my 25 year old furnace?

Age of your Furnace
If your furnace is pushing 25 years or more, it’s probably nearing the end of it’s effective lifespan. However, as already mentioned, this shouldn’t be the end-all-be-all in the decision. You might choose to replace a 15 year old furnace, or it could last more than 30 years.

Is it cheaper to replace furnace and AC together?

On its own, a replacement air conditioner can cost between $4,350 – $12,095. A lone replacement furnace can cost between $3,000 – $7,600. (Both of these ranges include the cost of the equipment, labor and other fees.) But you can save on labor expenses and fees when you replace both systems.

Are 80 Percent furnaces being phased out?

This is a big change coming in residential & light-commercial furnaces. Effective June 1, 2013, federal law requires that minimum furnace efficiency in the Northwest must be 90%. That means that 80 percent furnaces cannot be installed after that date.

What can you do with an old furnace?

Find a Reliable Transportation Service. Find a heating and cooling system removal service or a hazardous removal company in your local phone book. Contact the contractor and schedule a day and time to have them come and remove your furnace, if possible.

Is a 20 year old furnace still good?

Furnaces 20 years old or older become increasingly inefficient over time and can crack and leak, putting you and your family in danger. If your furnace is between 16 and 20 years old and constantly breaking down, then you should strongly consider having it replaced.

Should you replace a 30 year old furnace?

Regardless of the logic you follow, the 30-year mark is at or close to the maximum lifespan you should expect from your furnace. Even though furnaces can last 30 years or beyond, most experts recommend that you start shopping for a new furnace when your existing unit is 15 years old.