The answer to 'water heater frozen' is that a frozen water heater is a common problem during cold weather, typically caused by a lack of insulation or exposure to freezing temperatures. Symptoms include no hot water, water leaks, or a completely frozen tank. The solution is to thaw the water heater as quickly as possible to prevent further damage.
For a frozen water heater, the best approach is to call a professional plumber. Attempting to thaw it yourself can be dangerous and lead to more problems. A plumber has the tools and expertise to safely and effectively restore your water heater without causing further damage.