The answer to 'why is my faucet rusty water' is that the rusty water is typically caused by corrosion in the plumbing system or the faucet itself. This can happen over time as the metal components of the faucet and pipes start to break down, especially if you have older plumbing or hard water.
Some common symptoms of rusty faucet water include a reddish-brown tint, metallic taste, and staining of sinks or bathtubs. This is often a sign that the internal components of the faucet or pipes are deteriorating and need to be addressed. In some cases, it may be possible to fix the issue with a simple faucet repair, but more extensive plumbing work may be required if the problem is throughout the home's water system.