Smart doorbells, like the Ubiquiti G4 Pro, Ring, Blink, or Amcrest, bring convenience and security to your home. If your doorbell chime is making a persistent humming, buzzing, or rumbling noise when idle, it can be frustrating. This issue often stems from the way smart doorbells interact with your chime and transformer. Below, we’ll walk you through why this happens and how to fix it with a simple, affordable solution.
Why Does My Smart Doorbell Chime Hum?
Unlike traditional doorbells, which cut off power completely between rings, smart doorbells send a small amount of residual voltage (typically 3–4 volts) to the chime to power features like cameras and Wi-Fi connectivity. This constant voltage can cause the chime’s internal striker to vibrate, creating a humming or buzzing noise. For example, the Ubiquiti G4 Pro Doorbell includes a relay accessory to manage this voltage, but it may not fully eliminate the hum in all setups. Similar issues can occur with Ring, Blink, or Amcrest doorbells.
How to Fix a Humming Doorbell Chime: Step-by-Step
Before starting, ensure you’re comfortable with basic electrical work. If not, hire a licensed electrician for safety. Here’s how to stop the humming:
Step 1: Verify Your Transformer
If your chime isn’t ringing at all, your transformer may be underpowered. Smart doorbells typically require a 16–24V AC transformer with 20–40VA (volt-amperes). Upgrade to a compatible transformer if needed, then check if the humming persists.
Step 2: Confirm Residual Voltage Is the Issue
Use a multimeter to measure the voltage at the chime terminals when the doorbell is idle. If you detect 3–4 volts, this residual voltage is likely causing the striker to vibrate and hum.
Step 3: Add a Resistor to Reduce Residual Voltage
A 10-ohm, 5-watt resistor can reduce the residual voltage enough to stop the humming without affecting the doorbell’s functionality. Here’s how to install it:
- What You Need: A 10-ohm, 5-watt resistor (available at hardware stores or online for a few dollars). Here’s the link for the item on Amazon.
- Installation: Turn off power to the doorbell system at the breaker. Connect the resistor between the transformer and the front chime terminal (refer to your doorbell’s wiring diagram). Secure all connections and insulate the resistor to prevent shorts.
- Result: The resistor lowers the residual voltage (often by about half), preventing the chime’s striker from vibrating, thus stopping the hum.
This fix is effective for many smart doorbells, including Ubiquiti G4 Pro, Ring, Blink, and Amcrest, when residual voltage is the culprit.
Step 4: Test Your Doorbell
Restore power and test the doorbell. The chime should ring clearly when pressed and remain silent when idle. If the humming continues, verify the resistor’s connections, ensure it’s rated for at least 5 watts (to avoid overheating), or consult a professional to check your setup.
Tips for a Smooth Smart Doorbell Experience
- Check Transformer Compatibility: Confirm your transformer meets the doorbell’s voltage and VA requirements (e.g., 16–24V, 20VA or higher).
- Use a Mechanical Chime: Digital chimes may be incompatible with smart doorbells, leading to persistent issues.
- Remove Diodes: Some chimes include diodes that can cause humming. Check your chime and remove any diodes if present, as suggested by Ubiquiti’s support.
- Consider a Smart Chime: Devices like the UniFi Smart Chime can bypass mechanical chime issues entirely.
- Brand-Specific Support: Visit manufacturer support pages for Ubiquiti, Ring, Blink, or Amcrest for tailored advice.
Why This Fix Works
The 10-ohm, 5-watt resistor reduces the residual voltage reaching the chime, preventing the striker from vibrating while allowing the doorbell to function normally. This solution is widely recommended in smart home communities and has been successfully applied to various brands, making it a reliable fix for most setups.
Stop the Humming Today
With a simple resistor and a few minutes, you can eliminate the annoying hum from your smart doorbell chime and enjoy the full benefits of your Ubiquiti G4 Pro, Ring, Blink, or Amcrest doorbell. Don’t let a buzzing chime disrupt your home—try this fix and restore the silence!