It sounds like either the furnace is undersized, dirty, old, or the home is not insulated well. Make sure the filter is clean, all registers and returns are open and unobstructed, and have the heat exchanger cleaned and inspected by an HVAC technician.

Does outside temperature affect furnace?

The colder it is outside, the harder your furnace must work to keep the inside of your home comfortable. The harder your furnace works, the more likely it is that something will go wrong.

Why is my furnace not keeping up with the cold?





Inadequate airflow from your furnace into your home will keep it from being warm and cozy when cold weather arrives. If there is a problem such as a broken blower fan, a dirty air filter, or ductwork that has been damaged, the heated air cannot circulate throughout your home.

How hot should gas furnace air be?

With a conventional gas furnace, you should be at about 140°F-170°F at the supply plenum. A high efficiency furnace will be lower, around 110°F-140°F. However, the temperature at the outlet of the furnace, is dependent on the temperature of the incoming air.

How do I get cool air out of my furnace?

How To Troubleshoot Furnace Blowing Cold Air

  1. Step 1: Check Thermostat Setting. First and most importantly, make sure your thermostat is set to Heating Mode. …
  2. Step 2: Evaluate and Adjust Your Vents: …
  3. Step 3: Assess Furnace Filters and Replace Filters If They Are Dirty. …
  4. Step 4: Call An HVAC Pro.

Why is the furnace blowing cold air?





If your furnace is blowing cold air in your home, this is a sign of an issue with the flame detector, gas supply, air filter, pilot light, or condensate lines. Many of these issues are able to be easily solved on your own by sanitizing or replacing components in the gas furnace.

How long should furnace run in cold weather?

Industry research shows some expected time frames for how long a furnace runs during a particular cycle. Running 10 to 15 minutes per cycle seems acceptable. So is running as long as 20 minutes. Even running every seven or eight minutes may not be a problem, as other factors could lead to more frequent cycling.

Why is cold air coming out of my vents when the heat is on in my car?

Low Coolant Level

The coolant (usually a mixture of water and antifreeze) in your engine doesn’t just work to keep the engine from overheating: It’s also the source of heat supporting the heating system. If there isn’t enough coolant in your system, the heater core will blow cold air into your car.