Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Help,,Home Heating messing up

( I have a central HeatAC unit outside my home.I'm a DIY person. The problem is the heat(electric) won't blow out with the thermostat on AUTO. With stat on the Fan AutoHeat position there is a Click,,,,,,,,,,,,,,,,Click and it does this every min and a half with no heat blowing out. The clicking is coming from the central unit outside.
I have figured out that with the thermostat in the Fan ONHeat, the heat works and the air blows out just fine, but you have to turn Off to stop it.)

**** Now for the New information***
I found out some useful information. The first click is the heating coils turning ON and the second click there turning OFF. I found this out by putting my hand on top the heater duct out side the Unit. You can feel the heat(Big time) .
Now listen to this crazy stuff. I put the stat OFF and it still clicks,,you can feel the heat. I even put stat on AC ON,,, it clicks and there is heat Big Time. What is causing this?
Here is a link to some pics of heater,,

Thank,,,,, Joey


  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380
    Elecric Heat

    The control that is clicking is a bimetal safety switch that will open the circuit to the electric strip heater in the event that the temperature in the area immediately surrounding the heater gets too high. The very fact that this is happening is an indication of improper airflow through the air distribution system.

    In many cases, there are either sails switches or pressure switches that will close the verify airflow through the ducr system before the heating elements can be enregized.

    From the looks of the wiring in the pictures you posted, the wiring has been changed/altered many times since the system was initially installed. For this reason, I am led to believe that the heating system will not work as originally intended.

    A sample design sceme is as follows:

    Thermostat set to heating and the fan is in the AUTO position.

    The fan starts, but the heating elements are not energized.

    Once the pressure switch or sail switch closes, the heater circuits are energized.

    When the thermostat is satisfied, the heaters turn off.

    After a predetermined time period, the blower cycles off.

    Another option is to have the fan operating in the ON position and simply cycle the electric strip heaters on and off on thermostat. The important thing to remember is that you cannot energize the electric heaters at the same time as the blower. If the blower fails to operate or if there is insufficient airflow through the duct system, the heater area will overheat and you are at risk for a fire.

    The fact that the bimetal is clicking indicates that the system is definitely not wired correctly or, at a bare minmum, you have a blocked duct, dirty air filter or other obstruction in the air distribution system.

This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!