This is a double switch box in a bathroom. On my diagram the circles are wire connectors. There are three wires coming into the box, each with a black and white wire. There are two switches in the box, one for a light, and the other for a fan. The fan switch is a timer. The timer was working OK but started making a loud buzzing noise so I took the plate off and this is what I found. I wish to replace the timer with another timer. My question is: * should I go buy a timer that has a red, white and black wire coming out and just hook it up the same way? * does this box need to be rewired?
If I understand your drawing, any type of timer switch for your fan should work unless you have a small or crowded back box. Here is what your timer appears to have connected:
Red: Switched hot
Neutral is connected to the timer because the timer itself must be using power such as a light on the switch itself or the timer circuit needs power. If you were to buy a timer switch that was mechanically operated like an old fashioned kitchen wind-up timer OR replaced the timer with a regular switch, then you would not connect anything to the white wire nut. However, I think most timers will have 3 wires and not 2. Also, I can't see what your old switch looks like, but make sure you don't leave the old white wire still attached to the wire nut inside the back box.
Hope this all makes sense. The chances are that whatever timer you buy will come with instructions on how to hook it up anyway so you should be good.