Testing a Ceiling Mounted Electric Heater

By Dave Rongey - Summary:

Why did my electric heater stopped working? How To Test a Heater and Electrical Wiring, Possible Electrical Circuit Wiring Problem.

Electric Heater Problem

Electrical Question: Why did my electric heater stopped working?

  • My Nutone #157 surface mount ceiling heater stopped working.
  • I took down the unit using a coat hanger to allow the unit to hang from ceiling while checking it.
  • I removed the two wire nuts and probed the house wires with my voltmeter and found there was only 13volts.
  • I thought the 20 year old heater was bad so I bought a new unit.

The electrical wiring connections were easy:

  • Black on black, white on white, an easy fix.

I wired the new heater and it will not work either. I’ve checked the house wiring and it shows 13 volts. I don’t understand what is wrong. I didn’t check the old unit for ohms, but today I checked both units for continuity and they both appear to show open circuits.

This electrical question came from: Dennis, a Handyman from Dallas, Texas.
See more about Home Wiring for Texas

Dave’s Reply:
Thanks for your electrical wiring question Dennis.

How to Test a Heater and Electrical Wiring

Application: Testing an Electric Heater and Circuit Wiring.
Skill Level: Intermediate to Advanced – Best performed by a Licensed Electrician.
Tools Required: Basic Electricians Pouch Hand Tools and Voltage Tester.
Estimated Time: Depends on personal level experience, ability to work with hand tools and electrical troubleshooting skills.
Precaution: Identify the heater circuit, turn it OFF and then Tag it with a Note before performing any wiring inspections or testing.

Testing a Electric Heater Element and Circuit Wiring

  • Testing the Heating Element
    Make sure you are testing the heater correctly. This heating unit has heating elements which may appear to produce an open reading when checking for resistance and continuity.
  • In order to get an accurate resistance reading, the heat coils should be tested when the unit is not connected to the house wiring.
  • The tester should be set to the OHM scale, and each test lead should be attached to each wire connected to the heating elements.
  • The resistance reading will depend on the watt rating of the heating element, however if no reading is produced then the heating element is most likely faulty.
  • Testing the Electrical Circuit
    Because the heating unit was not working, the electrical power circuit should be checked.
  • Due to the high amount of electricity electric heaters require there is a high probability that the wall switch that controls the heater may need to be replaced.
  • Testing the wall switch for continuity will reveal if the switch is faulty or not.
  • The circuit wiring should be inspected for burnt or faulty connections or splices.

Do not use a tester while the circuit is on unless you fully understand what you are doing and the functions of the test equipment. These electrical components can be safely tested for fault while the circuit is off.

The heating elements will show resistance and should not show give a full open reading.

Possible Electrical Circuit Wiring Problem

  • Low Voltage Readings
    • If the wall switch is not the problem then there may be a problem with the electrical circuit, which would explain the low voltage reading of 13 volts.
  1. Electric heating units place a high load on the electric circuit and the neutral wire connections and splices often produce problems.
  2. Inspect all the electrical wiring of this circuit paying close attention to the white neutral wires.
  3. Burnt or damaged wiring will require repairs that produce clean solid connections that are tight and spliced properly.

More about Troubleshooting an Electric Heater Problem

For more information about Electrical Troubleshooting

  • Troubleshooting Electrical Wiring

  • Licensed Electrician Reveals the Secrets of Successful Electrical Troubleshooting Methods
    used to solve the majority of the home electrical problems and wiring failures encountered.

Using Electrical Testers and Voltage Meters
using an electrical tester

Understanding Digital Volt Meters

When working on home electrical wiring using voltage meter can play an important part in electrical safety.
Electrical testers and voltage meters enable you to identify electrical circuits and help prevent the possibility of accidental electrical shock.
Types of Electrical Testers

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» Click here to learn more about Home Electrical Wiring «
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Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all projects.


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