Rusty or discolored hot water can be caused by several factors:
1. Corroded water heater: Internal rust, especially in older tanks.
2. Sediment buildup: Mineral deposits settling at the tank bottom.
3. Rusty pipes: Corrosion in your home's plumbing system.
4. Recent maintenance: Stirred-up sediment after work on water lines.
5. Municipal water issues: Problems with the main water supply.
6. Anode rod failure: Deterioration of the sacrificial rod in the water heater.
7. High iron content: Naturally occurring in some water sources.
8. Bacteria growth: Can cause reddish-brown water, especially in well systems.
Regular maintenance and flushing of your water heater can prevent many of these issues.