Back to Blog

Image

Simple Problems That May Make Your Furnace Blow Cold Air


March 20, 2019


You
might think that a disastrous malfunction has affected your furnace
if the furnace runs but blows cold air. In many cases, however, the
issue is a relatively simple problem that you can solve without the
involvement of a professional. Here are some of these simple
problems.

Clogged Air Filter

A
clogged air filter restricts airflow to the furnace, and a furnace
with a restricted airflow can easily overheat. An overheated furnace
can easily break down and is also a fire hazard. Thus, furnace
manufacturers include a safety control device that shuts off the
burners if the filter is dirty and the furnace is about to overheat.

Thus,
the solution to your lack of heat might be as simple as a change of
air filter. This solution is even more likely to work if you haven’t
replaced the air filter in a long time, which means the filter is
relatively dirty.

No Pilot Light

In
a gas-powered furnace, the pilot light provides the high temperatures
necessary to ignite the fuel. Without a pilot light, the gas won’t
ignite, and your furnace won’t produce any heat. Several things can
blow off your pilot light:

The
pilot light may go off if its orifice is dirty.

The
pilot light may go off due to a strong draft.

The
pilot light may go off if the thermocouple – this shuts off the gas
supply in case the pilot light goes off – has malfunctioned.

The
solution here depends on the reason for the pilot light blow off. In
some cases, you need to relight the pilot light to solve the problem.

Poor Thermostat Setting

The
thermostat senses the room temperature and sends the information to
the main board of the furnace. The signals from the thermostat
instruct the furnace to continue heat production or turn off active
heating. For example, once your room temperature has risen to the
required temperature, the thermostat will signal the furnace to turn
off active hating.

An
incorrect setting in the thermostat may send the wrong signals to the
furnace and interfere with heating. For example, if someone sets the
thermostat fan to ON, the furnace won’t heat your house. You will get
heat again if you change the setting to AUTO.

Inadequate Fuel

Your
furnace needs fuel to produce heat; the fuel is usually natural gas
or oil. Thus, low fuel supply can make your gas furnace blow cold.
Here are some of the reasons your furnace might not get adequate
fuel:

The
natural gas supply is low – supply fluctuates with demand in a given
area.

The
gas regulator has malfunctioned, the gas pressure is low, and you
have multiple gas appliances. Your oil tank is empty – for those who
use oil-powered furnaces.

You
could reset the gas regulator or replace your oil tank and get your
furnace to produce heat again if those were the only issues. As for
low gas supply, contact your utility service provider if the problem
persists for a while.

Clogged Condensate Line

The
combustion process that produces heat in the furnace produces steam –
that condenses to water – as one of its byproducts. The furnace’s
condensate line channels the condensed water out of the furnace for
safe drainage.

Too
much condensation in the furnace is a safety risk. Thus, many
furnaces have safety switches that turn off the burners if the
condensate line is clogged and the condensation can’t drain out.
Clean the condensate line, and your furnace will produce heat again.

Hopefully,
you won’t have to deal with major problems if your furnace starts to
blow cold air. However, Comfort Solutions can help you diagnose and
fix all furnace problems whether they are relatively simple or
complicated. Contact
us

with all your furnace issues, and we will give you prompt service.