How do you test a doorbell transformer with a multimeter?

To test a doorbell transformer with a multimeter, begin by ensuring safety by turning off power to the transformer at the circuit breaker. Set the multimeter to the appropriate AC voltage range. Disconnect the wires from the transformer terminals to avoid any interference during testing. Place the multimeter probes on the transformer terminals—one on the primary input and the other on the secondary output. A functioning transformer should display a voltage reading near the transformer’s rated output value, commonly around 16-24 volts for doorbells. If the reading is significantly lower or shows no voltage, the transformer may be faulty and require replacement. Always remember to reconnect any components after testing and restore power to the system.