I've been shopping for houses and found this gadget in the garage. It's up near the ceiling and I don't know what it is for. There's nothing nearby that would give any hints. My image is unintentionally rotated 90 degrees counter clockwise. I'm looking up at it.

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I think I can make out 16v and 10 amps stamped on the frame. I initially thought it might be for the doorbell, but thought the garage is an unlikely place for it. I've never seen anything like this related to a garage door opener either.

The house was built in 2015. Thanks

  • Is it near the HVAC system? The transformer could be to power the thermostat.
    – DoxyLover
    Commented Feb 9, 2019 at 4:28
  • 2
    Disconnect it to see what device shuts off or stops working.
    – d.george
    Commented Feb 9, 2019 at 10:16
  • Dorbell transformer or thermostat transformer
    – DDS
    Commented Feb 9, 2019 at 11:15
  • In addition to doorbell/thermostat 2 other possibilities are a 1) lighted address sign—makers like making them low voltage because they don’t have to adhere to wiring standards, they may also be less expensive to operate—a claim made but I’ve never measured or calculated. Or 2) converted gas yard lights. These are post mounted fixtures that once burned gas. When converted it’s often as low voltage because the existing gas line can be used as conduit for the low voltage wire. Conversion kits are available online.
    – Tyson
    Commented Feb 9, 2019 at 23:27

3 Answers 3


Looks to me like a doorbell transformer.

  • Certainly some sort of low voltage supply. Commented Feb 9, 2019 at 14:58
  • After doing the 3D walk through earlier today, I noticed the doorbell in the hallway on the same wall inside the house. So I'm pretty certain you're correct. Thanks! Commented Feb 9, 2019 at 23:31
  • Easy way to find out is disconnect one wire then try the garage door and the doorbell and see which one does not work.
    – Alaska Man
    Commented Feb 10, 2019 at 4:39
  • Normally I would consider that, but it's not my house. Commented Feb 12, 2019 at 23:42

Since it is in the garage I would say it is a transformer for the garage door opener and safety Beam that stops the door from coming down if something obstructs the beam.


It's a doorbell or thermostat transformer. That wiring method is legit because the low-voltage is on the outside.

Normally this sort of thing is placed in the unfinished utility spaces, but my guess is this house doesn't have any.

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