Unplug your Jenny pressure system from the wall unit.
Drain any water or liquid inside.
Mix 1 part white vinegar with 2 parts water in a small bowl.
Pour the vinegar solution into the reservoir.
Plug in your Jenny pressure system, and turn it on.
Allow the system to run until the vinegar solution is half gone.
Turn the system off.
Leave the solution inside while it cools down.
Drain the remaining vinegar solution from the system.