How to Troubleshoot Electrical Sequencers

Sequencers intermittently shut off electrical fireplaces to prevent a blown fuse.

An electric sequencer is a device, often used on electrical fireplaces, that intermittently shuts off power to an appliance to prevent a dangerous surge in power. When the sequencer does malfunction, it prevents the entire electrical system from working. Troubleshoot your electrical sequencer if your electrical appliance no longer turns on. A simple visual inspection and some tests with a multimeter can determine whether or not your sequencer is causing the problem of if you need to look elsewhere.

Things You'll Need

• Screwdriver
• Multimeter

Instructions

1. Turn off all the power to the electrical appliance. No power can run through any of the circuitry before you remove the sequencer.

2. Disconnect the sequencer from the electrical appliance using a screwdriver. Place the screw in a safe location as to not lose it before you refasten the sequencer.

3. Inspect the sequencer for physical damage. If the sequencer failed, a dangerous power surge likely occurred, which caused the sequencer to burn. The sequencer has a charred appearance and the terminals at both ends sometimes burn off when this occurs. Replace the sequencer if you see this damage.

4. Test the resistance of the sequencer by placing a multimeter's prongs at the end of both terminals. A typical reading for a fully functional sequencer is 20 ohms. Any other reading indicates a possible malfunction.

5. Change the settings on the multimeter to a continuity test. A continuity tests detects an electrical connection between two points. Most multimeters use a buzzing or ringing sound to indicate continuity. Place the two prongs on the two terminals and wait for the sound. Replace the sequencer if the multimeter cannot detect any continuity.

References

• HVAC For Beginners: Electric Furnace Sequencer Replacement, Do it Yourself and Save...
• Arnold Service: Electric Heat Repair Parts