Office & commsCommon
Doorbell
Also called chime, doorbell transformer.
A solenoid chime and, somewhere near the panel or in the chime box, a small mains transformer at about 16 VAC. Wireless buttons are just a battery and a radio you will not reuse.
A donor is the dead machine. The parts below are what is still worth removing from it. “Leave it” is a part that is physically in there and should stay in there: too dangerous, too worn, or only useful as part of a repair you are not doing.
A scrapped machine is a box of parts that failed at different times. The reason it was thrown out is often one bad piece. The motor, the cord, the supply, and the screws are frequently still good. This index says which is which.
Why it is in the trash while the parts are not
A remodel, or the wireless button's battery leaked and someone replaced the whole set.
Before you open it
Do this while it is still unplugged, cool, and not leaking. Find the breaker. The primary is mains.
Where the dead machine usually is
- Remodel and construction dumpster — Curb
- Laundry and utility closet — In the house
- Living room and entertainment stack — In the house
The transformer is often left on the panel when the chime is removed. Kill the breaker.
How it comes apart
Chime cover pulls off. Two plungers and a spring on the classic two-note chime.
Tools: Screwdriver, Meter, Voltage tester.
Words on this page
- mains
- Ordinary household wall power. It can kill. Unplug before you open anything that used it, and do not experiment on live wiring.
- solenoid
- A coil of wire with a metal plunger that pulls in when the coil is powered. The travel is short, a few millimetres.
- transformer
- Two coils on an iron core. It changes voltage and, in a proper one, isolates the output from the wall. Heavy old adapters are this. Microwave oven transformers are a different, dangerous kind.
What to take
The table is the short version. The notes under it describe that part inside this machine, not only the general description.
| Part | Call | How many | How often | Where to look |
|---|---|---|---|---|
| Doorbell transformer | Prize | 1 | usually | At the panel, or in the chime enclosure. |
| Solenoid | Prize | 2 | usually | The chime. |
| Panel switch | Worth pulling | 1 | usually | The button. |
| Spring | Bonus | 2 | always | Return springs. |
| Coin cell | Bonus | 1 | sometimes | Wireless buttons. |
Prize
8–24 VAC, commonly 16 V, 10–30 VA.
At the panel, or in the chime enclosure.
Breaker off. Confirm dead. Then it is a normal small transformer.
Good.
Two coils and a plunger, low-voltage AC.
The chime.
Take them with the springs.
Good.
Worth pulling
A simple contact, sometimes lighted.
The button.
The light is across the contacts and only works in the circuit.
Good.