I've installed a tankless water heater and discovered that my pump does not provide the flow/pressure necessary to keep the unit on. I've a new 42 gallon pressure tank on the system and I have no idea how old the pump is. I also have now idea how deep the well is. We've lived here ten years and have had no problems with it. I guess we've just gotten used to the low pressure. So, the question is, will replacing the pump and motor improve the continuous flow/pressure enough to keep the tankless unit on?