We were told by the water company to check out running toilets (leaking continually). We shut one off upstairs not being used but we still have water loss somewhere. I suspect the water heater in the basement. There seems to be a lot of noise coming from the drain off the water heater that goes into the floor drain (I think it's for condensation but sounds too busy). What kinds of water heater issues could cause this? Am I looking the right direction?