Water heater leaks can be the worst depending on where the water heater is located in the home. Water heaters in attics or closets inside of the home can cause water damage to floors, walls and ceilings. Rising pressure can cause the water heater to explode, however your system has a pressure relief valve to hopefully avoid that from happening. An increase in pressure will cause the pressure relief valve to open in turn making the water heater leak. Be sure to call a professional to repair or replace your water heater as sometimes this can be a dangerous and complicated fix.