water inlets

[dustym]

I have a Holiday rambler Alumascape and it has 3 water inlets. I know 1 is for city water, 1 is for filling the tank, and the 3rd looks like it goes to the hot water part of the system. While is was rinsing the hot water tank, I thought I could put the hose to it to help flush the tank. No water was going into the tank, and I didnt know where it was going,so I stopped. Can anyone tell me what its for?
Thanks,

 

[campnfool]

That 3rd one may be the black tank flush.

 

[John From Detroit]

There is normally an inlet for fresh water, Depending on the RV there may be a 2nd one for filling the fresh water tank or there may be a diverted valve for that (Or on one RV I saw a float valve controlled electric solenoid, you press a button and it shuts itself off.. Anyone got say a half million lying about you can buy a rig just like that).

And the 3rd would be black tank flush

Another config, one I hope to install some day

City water (Fresh) inlet both for tank filling and use (Diverter valve set up)

Black tank flush
Gray tank flush.

But I have yet to get a 2nd Tornado for the gray tank or enough urge to install.. This month upgrades are out as.. Well I just replaced the house batteries... The new ones are heavier. (I can not lift them from the ground to the motor home while lying on my back, (how you install them) I could the old ones).

 

[dustym]

Only reason i ask, is cause it is red tubing just like the hot water system in the rest of the trailer.