Wireman · Doorbell not ringing: troubleshooting for electricians · 2023 NEC ·
Doorbell not ringing
Transformer, button and chime, plus video doorbells that need more power.
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How it works
A wired doorbell is a small circuit: a transformer steps 120 V down to low voltage (commonly 16 V AC), one wire runs through the button, and the button completes the circuit to the chime. When you press it, the chime’s plunger strikes the bars. Video doorbells replace the button and need more power from the transformer than a plain button does, so an old, small transformer is a common problem.
Every question and answer in this guide. Tap “Step by step” to walk through it.
- What kind of doorbell is it?
- Plain buttonDoes the chime make any sound, hum or buzz?
- SilentTest: Measure the transformer outputExpect: At or slightly above the voltage printed on it, often around 16 V AC.
- About 0 VDead transformer or no 120 V
- Normal voltageTest: Test the button by touching its wires together
- Chime ringsBad button
- Still nothingTest: Measure voltage at the chimeExpect: About the transformer voltage while the button is pressed.
- Voltage present, no ringFailed chime
- No voltageBroken or loose wire
- Hums or buzzes all the timeStuck or shorted button
- Just a weak thunkDirty chime plunger or weak transformer
- SilentTest: Measure the transformer outputExpect: At or slightly above the voltage printed on it, often around 16 V AC.
- Video doorbellWhat is the video doorbell doing?
- Reboots, drops offline or battery drainsTransformer too small for the video doorbell
- Works, but the indoor chime doesn’t ringChime type or kit setting
- No power at allTest: Measure the transformer outputExpect: At or slightly above the voltage printed on it, often around 16 V AC.
- About 0 VDead transformer or no 120 V
- Normal voltageTest: Test the button by touching its wires together
- Chime ringsBad button
- Still nothingTest: Measure voltage at the chimeExpect: About the transformer voltage while the button is pressed.
- Voltage present, no ringFailed chime
- No voltageBroken or loose wire
- Plain buttonDoes the chime make any sound, hum or buzz?