If you have a furnace that is not heating to keep your house warm, this can be due to many things. Below are two of these things so you can determine what is wrong and get your furnace repaired.

Thermostat Problems

First thing to check is the thermostat. Look at the temperature to see if it reads correctly. If it does not, turn the furnace up and see if this works. Also make sure the thermostat is set to heat, as someone could have set it to cool, especially if you have had hot days.

If the thermostat still reads the wrong temperature, turn the fan off and on to see if this activates the furnace. To do this there should be a switch on the thermostat that is labeled fan. Flip this switch in the opposite direction and wait a few minutes. Flip it back to the original position and see if the fan turns on. If it does, the temperature on the thermostat should start going up.

If this brings the temperature up, you need to replace the thermostat. If your current thermostat is old, you will find the newer ones have a lot of options. For example, there are digital thermostat that allows you to preset temperatures, such as automatically turning the thermostat down during the night time hours. The type of thermostat that will work does depend on the furnace you have. A professional can help you choose what would work best.

Air Filter Problems

A common cause of a furnace not heating is a dirty air filter. When dust and dirt are built up on the filter this restricts the air flow. If the air filter is too clogged, this will cause the heat exchanger to overheat. If this happens, the heat exchanger will automatically turn off. If the air filter is dirty the blower will run but no heat will come out of it. Soot will build up on the heat exchanger also. This will cause your furnace to work much harder to keep your home heated, which will in turn shortens the life of your furnace.

Look at the owner's manual for your furnace to determine the type of filter you need to purchase. You can buy the filter at a home improvement store.

If you use flat, inexpensive filters, replace them approximately every 30 days. Pleated filters should be replaced approximately every 90 days. This will be more often if you have pets that shed, if someone smokes in your home, or if there is anything that generates a lot of dust.

Contact a furnace installation and service contractor to look at your furnace if you cannot get it to heat well for you.