Furnaces require some sort of ignition in order to heat colder air and send it up the ducts into your home. If you are not getting warm air through the vents and it is just blowing cold air, the problem might be with your furnace’s ignition. It typically isn’t something you as a homeowner can fix either, so be sure to call an HVAC technician.
Electrical
Electric ignition switches in a furnace are connected by wires to a switchboard and need electricity to work. If the electrical wires are fried, disconnected, or not working, this is the source of your ignition problem. Reconnecting and/or replacing the wiring resolves the issue.
Mechanical
In gas and oil furnaces, the ignition has components that are triggered to click and ignite the fuel in order to heat air. The components of these switches can break off or come loose. Broken or loose parts will not be able to ignite fuel and heat your home, but that’s not the half of it.
Oil continues to pump into the ignition chamber, creating a mess that has to be cleaned out before the switch can be fixed. If you use gas to heat your home, the lack of a functional ignition switch leaks gas into your home creating the perfect storm for an explosion. If either of these apply to your furnace, cut off the fuel and get out of the house before calling for help.
Functional
Sometimes parts just don’t function like they should. There doesn’t appear to be anything wrong with the ignition, but it just doesn’t work. When that happens the only thing that can be done is to replace the ignition completely. Your HVAC repair technician will have the correct ignition for your furnace make and model.
All Causes of Faulty Furnace Ignition Need Repair
You can’t fix anything electrical, mechanical, or functional with your furnace safely. For that, you need an HVAC technician. It’s also smarter to hire the pro because the pro will make sure everything is installed correctly and won’t start a fire later.