A furnace is an appliance that should keep you and your house nice and warm regardless of the cold temperatures outside. When some of its components develop problems, the furnace might blow cold air instead of hot air. If it happens only at night, the following tips will come in handy.
Problems with the furnace burner, thermostat, circuit control, or flame sensors commonly make the furnace cold air only at night. Obviously, this isn’t a problem that you should postpone solving and you have to troubleshoot it immediately. The standard solutions are cleaning, repairing, replacing the defective parts or resetting the furnace.
There are several causes why the furnace blows cold air and only at night. Problems with the thermostat, the circuit control, the flame sensors, or the furnace burner represent the most common causes.
Sometimes, you might have set the thermostat to cool, which is why the furnace blows cold air. Maybe you forgot about it when you set it to cool in the summer or during the last heat period.
Circuit control
The circuit control of the furnace resembles a lot to a processing unit. It collects information from the thermostat and sends the correct information to the furnace. When the circuit control is defective, it might switch on the furnace’s blower without activating its burners.
Furnace’s burner
When debris clogs the burner, the furnace will start blowing cold air. It happens as the built-up debris will stop the burner from getting ignited. When the burner becomes clogged, the furnace will blow hot sometimes and cold at other times.
Flame sensor
The flame sensor is an essential component of the furnace. Whenever it develops issues, the furnace won’t be able to operate as it should. When the flame sensor isn’t in good condition, the furnace will no longer generate heat to its coils. It won’t take long until the burner turns off because of improper flame sensor operation. Therefore, the furnace will work for a short amount of time until stopping altogether. It could blow hot air during the day and cold air during the night.
How to stop the furnace from blowing cold air at night
Problems with flame sensors aren’t the only reasons why furnaces blow cold air at night. The best way to solve the problem is to troubleshoot and fix the problems you find. Here’s how to troubleshoot the furnace:
Switch on the power to the furnace
It’s essential to see if the furnace is still connected to the electrical supply. You have to check the power connection to ensure the electricity is present. Examine the circuit control to establish its functioning and see if the circuit breaker has tripped off. When the furnace isn’t connected anymore, you need to connect it to electricity. The faulty circuit control will need to replace or repairs and you should switch the circuit breaker back on if it’s tripped.
Check out the thermostat
Inspect the thermostat and see that it’s set to your needs. You should set the thermostat to the desired temperature and on AUTO, not ON or OFF. Should the thermostat cause further problems, you might need to look into it and even replace it.
Take a look at the furnace blower
You also need to check out the furnace blower and make sure it’s appropriately operating when you turn the thermostat on. If the blower doesn’t come up, remove it to take a good look at it. In case of damage, you have to call the professionals for resetting.
