Can One Transformer Power Two Door Chimes?

Short answer

Yes, one doorbell transformer can power two door chimes in some wired systems, but only when the transformer has enough VA capacity for both chimes and the wiring is correct. If the chimes buzz, ring weakly, or the transformer gets warm, stop and check the transformer rating before continuing.

What to check first

• Transformer voltage: many wired chimes use 16V, but always match the chime instructions.
• VA rating: two chimes need more capacity than one. A 16V 10VA transformer may be too small for two mechanical chimes or a video doorbell plus chime setup.
• Chime type: mechanical, electronic, and video-doorbell-compatible chimes can have different power needs.
• Button count: two chimes is a separate question from two doorbell buttons; front/back button wiring adds another layer.

When a larger transformer is the fix

If both chimes should ring from the same button, a higher-capacity transformer is often the cleanest fix. Many video doorbell and multi-chime setups use a 16V 30VA transformer, but the correct size depends on the chime and doorbell manufacturer requirements.

When not to use one transformer

Do not keep adding load to an old transformer if the system already rings weakly, hums, or has intermittent power. Those symptoms usually mean the transformer is undersized, failing, or wired incorrectly.

Products and next steps

For replacement power, compare the doorbell transformer category and the 16V wired doorbell transformer. If you are also replacing the chime, review the wired doorbell category. For any wiring inside an electrical box, use a qualified electrician.