I am having hot water supply issues with an electric water heater connected to a gas boiler for my baseboard heat. The hot water heater is 4 yrs old and i have the uppr and lower elements set on approx. 125 degrees. My tennants are telling me that the hot water supply barely lasts for 1 ten minute shower. It used to last longer than that but we always had minor problems with the hot water when we lived in the house. The circulator pump was changed out on the boiler as well as the whole system flushed and refilled and purged of air. Any suggestions why so little hot water? Could it be the 4yr old water heater is bad?