• Furnace shuts off/on, house never warms up


    My furnace comes on and runs from 2 to 5 minutes then shuts down. It will come back on by itself then shuts down again. It never gets the room up to temperature.

    diane, Bridgeton, MO

    When your furnace performs in this way, there are several possible causes. The heat anticipator setting on your thermostat will sometimes shut off the heat before the air inside the thermostat actually reaches the set temperature. You may find that some parts of the house reach the set temperature before the part of the house where the thermostat is located. This gives the heat time to reach the thermostat. The rate at which heat is delivered to your house varies slightly depending on the heating system type. Other reasons your furnace could be shutting off and failing to warm up the house include: the furnace getting too hot and cutting out on limit or a dirty flame sensor (a device which indicates that a flame is present as a part of the furnace’s safety circuit design). The flame sensor should be cleaned once a year and, at the same time, you should have a complete safety check. To determine the exact cause of your furnace issues, it is important to have your equipment checked out by a professional HVAC contractor, such as the ARS/Rescue Rooter branch serving St. Louis and the surrounding area at (314) 963-3242 or (636) 343-6555.