For a complete list of available spares please visit www.showerdoc.com
Water inside a new unit
Assuming you received the unit in a sealed box this is normal. Some manufacturers test units before sending them out. Water in a new shower unit is generally a good sign as you know it has been tested by the manufacturer.
Water leaking from the Pressure Relief Device (PRD)
The Pressure Relief Device is a safety mechanism on the bottom of the heating tank.
It's fairly easy to replace however there is usually something that causes it to blow: such as a kink in the hose or a blocked shower head. These should be checked before fitting a new PRD.
A new Pressure Relief Device can be purchased from: www.showerdoc.com
Galaxy Aqua 3000 Manuals and Fitting Guides
Galaxy Aqua 3000 Electric Shower Manual