How to Test an Electric Baseboard Heater

Over time, the resistive elements in your electric baseboard heater may fail. By testing the resistance of the heater, you can determine whether you need to replace the unit.

What You Will Need:
  • Screwdriver
  • Ohmmeter
  • Wattage and voltage specifications of your heater
Step 1 - Turn Off the Power

You want to be sure that, in addition to the thermostat, the breaker to the heater is turned off.

Step 2 - Calculate the Resistance

Resistance is measured in ohms. In order to find the resistance you will be testing, divide the heater’s wattage by its voltage to find the amperage; then divide the voltage by the amperage to find the ohms.

Step 3 - Connect and Test

Using a screwdriver, remove the cover from the heater to expose the wiring. Connect the red and black leads of your ohmmeter to the two wires going to the heater (red in “ohms,” black in “com”). The resistance reading should be very close to your earlier calculation. If the reading measures zero, or is very high, there is most likely some sort of short in the heating element. In this case, you need to replace it.

How to Stop a Furnace Fan from Running Continuously

During certain seasons of the year when you find it necessary to run your AC or furnace, you may find that your furnace fan is running continuously. Typically, this is caused by an incorrect setting on your thermostat, a defective thermostat, or by a furnace limit switch that needs to be adjusted or replaced.

Tools and Materials Needed

  • Flashlight
  • Screwdriver
  • New thermostat
Step 1 – Check Your Thermostat

Check the settings on you thermostat. If the fan setting is turned to "ON," switch the setting to the "OFF" position or the "AUTO" position. If the switch is already turned to either if these last two settings, check your AC/Heat register to see if hot or cold air is coming from the vent. If you feel room temperature air, the problem could be with the limit switch.

Step 2 – Check Your Limit Switch Settings

Find your AC system user’s guide and follow the directions you find there for resetting the switch's pointers you'll find on the limit control's "Fan" side. If you are able to see these pointers, check to see that the lower one is set at approximately 90 degrees F. The higher one should be at approximately 115 degrees F.