When your heater fails, you have a decision to make. Should you make some repairs to the existing unit, or should you just replace it? If the system is older and something major like the blower motor fails, you are usually best off buying a new heater since the cost of repairs may be close to the cost of a replacement. However, there are some smaller repairs that are definitely worth making, especially if your furnace is on the younger side (less than 10 years old.) These repairs won't cost you a fortune, and in most cases, once they are made, the furnace will keep chugging along for many more years.
The igniter is a little part that sits near the burner. Its job is to get hot enough to light the flame in the burner when gas starts flowing. In most furnaces made over the past few decades, the igniter is an electrical component. If it fails, then the burner won't light, and you won't have any heat at all. Depending on how your furnace is made, air may or may not keep flowing through the vents — but it definitely won't be warm.
The igniter is small and easily replaced. There may even just be a problem with the wiring that leads to it; your HVAC repair company can repair the wiring accordingly.
The thermocouple is another little component near the burner. Basically, it senses whether or not the burner and surrounding area are hot. If it's not hot enough, the thermocouple will stop the flow of gas so that you don't end up with gas leaking all over the place. If the thermocouple breaks, then there won't be any gas flowing into the furnace, so the burner won't be able to light. Again, you'll have a complete loss of heat when this happens. A thermocouple itself only costs a few dollars, and it might take your HVAC technician an hour or two to replace.
Blower Motor Belt
Sometimes your blower motor may sound like it's failing. It might make all sorts of screeching and squealing noises, even though the furnace is still warming up the air. This problem sounds worse than it is. Usually, your blower motor belt is just frayed. If you act quickly before the problem causes any other blower motor issues, then this should be a rather simple repair. Your tech only needs to undo a few screws to remove the belt and put a new one on.
For more information, contact a heating repair service in your area.