Embodiments of the present invention involve a refill apparatus comprising at least one pump, a plurality of reservoirs, a plurality of reservoir fluid channels each associated with one of the reservoirs, a plurality of valves, each having a cracking pressure, for fluidically sealing the reservoir fluid channels and the outlet fluid channel, an outlet fluid channel fluidically connected to the reservoir fluid channels, and a needle having a lumen in fluid communication with the outlet fluid channel. A parameter such as a pressure level is monitored, and one or more pumps and various ones of the valves are actuated in accordance with a protocol comprising a sequence of steps whereby fluidic pathways are opened between different ones of the reservoirs and the needle in a washing and filling sequence, each of the steps being associated with an expected pressure level.