To clean a water heater is very crucial and one of the things you can use to clean it is vinegar. You may either carry out spot or deep cleaning. When spot cleaning your water heater, mix water with vinegar in equal portions and spray the mixture in the tank. Rub a clean cloth around the tank to clean the tank without rinsing. If you need to deep clean, then you need to completely empty the tank of all the water then half fill the tank with vinegar. Pour out the vinegar after 30 minutes. Scrape the sides to remove all build-up in the tank and then wipe the tank and rinse thoroughly.