Add water to class A while boon docking

For some reason the onboard pump works to transport water inside the coach, but won't when trying to use the suction port to fill the water tank from a non pressurized system. Anything I could check to troubleshoot? I maybe doing it wrong...been known to happen:o
Scondly, If I use a portable pump attached to a drill will this fill the tank if set on tank fill on the service panel?
Inquiring mind needs to know...thanks