My son bought a house built in 1950. I am trying to get a nest doorbell working. His wires are cloth covered. Is that normal for 1950. He has two transformers. One is 16.7v for the door bell. What could the 25v be for. He has a defunct intercom and defunct heat sensors. Could it be for either of them. Finally it looks like the chime is set up for two doorbells but there's no trace of the second one. Could it be anything else.
In the unlikely event anyone knows about nest doorbells... He installed it and it worked for two years except that the chime didn't ring but their nest mini did so it was okay. One night the chime started buzzing loudly and they disconnected it. They bought a new chime but they couldn't get anything to work. I find 16.7v at the doorbell a green light is on the nest and shorting the wires makes the chime ring but nest doesn't do anything. The instructions say the voltage is inadequate but I think that is wrong. I think the nest
Is simply broken. Any advice.