Quote Originally Posted by CoChris View Post
By "auxiliary fill" I assume you mean the "city water" inlet. If so then yes, the water pump is on the same line as the city water use when filling the water tank. Note: You would not want to have pressurized water supplied to the inlet AND have the pump on. Usually one or the other. There are four common configurations/uses of the valves.

1) 1st diagram "City water". Use city water pressure to supply the fixtures (faucets). Water pump is turned off.

2) 3rd diagram "Sanitize". No water pressure at inlet. Use water pump (turned on) to draw (suck) water into water tank. Typically used to pump a sanitizing solution (bleach) into tank to sterilize. Can also be used to fill water tank from a non-pressurized water source (like a bucket).

3) 4th diagram "Power Fill". Use city water pressure to fill the water tank. Water pump is turned off.

4) 5th diagram "Winterize". No water pressure at inlet. Use water pump (turned on) to draw (suck) anit-freeze into system and distribute to fixtures.

Hope this helps explain the use. Is is really a question of what (city water or the pump) that pushes water through the system.

Chris
I think it's a momentum thing. There are two tank fill options, one through the Nautilus and an auxiliary, likely to help fill the aux faster. The auxillary looks like another black flush.