There are few things worse than waking up to a cold house because your furnace quit working. Added to the fact that everyone in the house is uncomfortable is the fact that you are going to have to pay the repair bill, which will cost more because it's for an emergency visit. All of these together add up to the fact that if you had paid attention to the furnace you might have been able to catch the fact that something is wrong long before the unit quit working. Here are a few things you need to pay attention to if you want to avoid a cold morning and large repair bill.
The only sounds you should hear from your furnace are the soft "woosh" sounds it makes as it cycles on to raise the temperature and possibly the whirring of the fan as it pushes air through the vents. If you hear knocking, banging, or screeching something is wrong. If you pay close attention, you should notice strange sounds when they first appear. This is the time to contact a furnace repair company to make an appointment. It is possible that the needed repair is something simple like a bolt that came free and is rolling around in the unit somewhere. However, if you wait, that bolt could cause damage to other parts, meaning more repairs are needed.
If your furnace is not heating your home to a comfortable temperature, there is a problem. While it could be something as simple as inadequate airflow due to dirty vent filters, it could be something more serious. A repair technician can diagnose the problem and let you know if you need new filters, need to have the vents cleaned and sealed, or if there is something else that needs to be addressed and repaired. You should have the system blowing warm air out again in a few hours.
If you notice odd smells coming out of the vents with the warm air, you should shut the system off and call for a technician. You do not want to damage any parts or have a fire break out. In most cases, smells from a furnace are related to friction, smoldering parts, or gas leaks.
Have your furnace serviced each year before it is time to turn up the heat. The service technician will get a good look at the inside of the unit and may be able to fix something before it actually becomes a problem. The sooner any small problem is noticed and repaired, the less likely you will wake up to a cold house.
To learn more about furnace repair, contact an HVAC contractor in your area.