If your furnace turns on but then shortly turns back off, and the temperature is dropping inside your home, it's time to call an HVAC service repair professional. There are many things that could be causing your furnace to shut off, and the professional will need to look inside the machine.

The age of your furnace may also be a factor, and you may need heating replacement solutions. Talk with a heating repair contractor about the state of your furnace and these specific concerns.

Faulty Sensor

The sensors in the furnace will detect if the furnace is getting too hot inside or if the unit is overheating. If the sensors aren't working properly and are faulty, this could be signaling that the furnace is overheating and then the furnace will shut down. 

Overheating Dangers

An overheating furnace is a danger to your home and safety. If the furnace is overheating shortly after the furnace kicks on, this could mean that:

• The blower motor or fan components need to be replaced to move air out of the furnace
• The pilot flame is getting too large and too hot
• There is a blockage in the ducts preventing heat from traveling through the ventilation system

This is something that needs to be addressed right away. If this is the danger, you don't want the machine running at all.  

Thermostat Complications

If the thermostat is sending mixed messages to the furnace, this could be why it starts and then shuts off. Resetting the thermostat may not be enough. If it's necessary to replace the thermostat you want a unit that can be set on timers, that gives wireless updates and has wireless controls, and that will notify you if the temperatures in your home get too hot or too cold at any given time. This will let you know if the furnace went out when you aren't home.

You don't want to wait until you have a danger in the home like a fire, or when the temperatures drop, and you don't have heat to get a hold of a heating and cooling repair expert. Instead, get the problem fixed and repaired as soon as you notice that there is a problem and that you are without heat.

The service professional can overlook your entire unit. If the unit is old and has major complications, it may just be time to find heating replacement options and you should upgrade to an Energy Star-approved furnace.