Homeowners face expensive emergency water heater repairs with no clear DIY diagnosis path

Homeowners with leaking water heaters face urgent, costly problems (potential water damage, no hot water) but lack clear diagnostic information to determine if they can DIY fix it or need an expensive plumber visit. Current solutions (generic manufacturer manuals, fragmented forum posts) don't provide step-by-step troubleshooting for specific leak locations, leaving people uncertain whether a $200 repair or $1,500+ replacement is needed.