Gas furnaces are a popular choice in many homes, since powering a furnace with natural gas is typically more affordable than electricity, especially in very cold climates where the furnace runs often in the winter. While gas furnaces are typically a durable and reliable source of heat, they can experience some problems that require repair, especially if the furnace is old. Some of the most common issues you may encounter when your gas furnace is in need of repair include:
Lack of Heat
It can be quite alarming to turn on your furnace on a freezing winter night only to notice that it is not producing the amount of heat that it should. This problem can be caused by several different issues. One possibility is that the gas valve may have been closed while the furnace was running, limiting the amount of gas that is available for combustion. It is also possible that a lack of heat is caused by a faulty thermostat; when a thermostat no longer works properly, it will need to be replaced by an HVAC technician. A blown fuse can also prohibit the furnace from producing heat.
A Continually Running Blower
When the furnace has stopped producing heat, the blower fan should also turn off. When the blower fan continues to run even when the furnace is not on, it is a sign of a problem. The first thing to do is check the thermostat to determine if it is set properly-- it should be set to "heat," not "fan." If the thermostat is set properly, the blower fan may continue to run due to the fact that a control switch on the fan needs to be replaced, or there may be something wrong with the fan itself.
Strange Noises While Operating
After living in a home for an extended period of time, people tend to know what their furnace sounds like when it is on. When a furnace begins making strange noises while operating, it is usually due to an issue with a component of the furnace. A noise that is high-pitched may mean that there is something wrong with a belt or the motor. Rumbling sounds often indicate that the pilot light is not lit properly or the burner is dirty and needs to be cleaned. The best thing to do is contact a furnace repair professional to diagnose and repair the issue when your furnace sounds odd.