The answer to 'my faucet installation smells bad' is that a foul odor coming from a new faucet installation is often caused by a buildup of bacteria or other organic matter in the plumbing. This can happen when the new faucet is not properly cleaned and sanitized before installation, or if there is a problem with the water supply.
Some common causes of a smelly faucet installation include: leftover debris or dirt in the pipes, bacterial growth due to standing water, or a problem with the water source like well water with high mineral content. The smell may also be caused by a faulty seal or gasket that is allowing air to enter the system.