1.) Filters And Ductwork

In order for that nice warm to reach you it has to go through your air filter(s) and ductwork for your unit. A dirty filter will clog the airflow of your system which will slow the air, causing your system to work longer and harder. Ductwork is vital in any home HVAC system and if there are leaks, blockage, or maybe even a whole piece of the ductwork sliced, air is going to escape the ductwork and not reach you. Imagine a scenario where there is a lot of air leakage in the ductwork and a dirty filter, you’re going to be losing out on efficiency. You might just need to change your air filter and/or have the ducts sealed up.

Filters Can Also Affect The Heat Exchanger

The heat exchanger is necessary to transfer heat to the air in your home. A dirty filter could have caused some kind of dirt or soot build up on the exchanger that is preventing any heat transfer. This problem will require a technician.

2.) Electrical Problems

While furnaces combust gas in order to produce heat they need electricity for the igniter, thermostat, and circuit breakers. Igniters do what their name implies, they use electric ignition to combust gas that produces heat for your home. The igniter could be bad or there is a bad electrical connection preventing it from starting. The thermostat is the brain of the whole system, it could be the cause of no heat due to bad electrical connections, it may just need batteries, or it has completely malfunctioned and you need a new one. Finally, all the power in your home goes through the circuit breaker box, if for some reason it is not supplying electric to your furnace then an electrician is necessary. Electrical problems can cause several components to malfunction and prevent proper operation.

3.) Blower Motor

In order for any air to be distributed throughout the ducting, the blower motor is vital for furnaces. First, it could have gone bad because of increased work load from dirty filters that caused it to overwork and some additional wear and tear throughout the years. Depending on the type of motor a run or start capacitor could have also gone bad. A bad run capacitor will prevent it from running and a start capacitor will prevent it from starting. Your blower motor might be the reason you’re not getting any comfy warm air into your home.

4.) Gas Supply

Your furnace may not have gas being supplied to it or the pilot light has gone out or possibly has malfunctioned. If your pilot light is out then as a safety precaution the furnace prevents gas from being supplied. Some people are comfortable lighting their pilot light, if your one of those people and it doesn’t work then you may not have any gas. Try using another gas appliance in the home to see if there is gas, like a stove. A pilot light might just need to be relit or your gas is not being supplied for some reason.