How to fill freshwater tank on 2015 MXT 303

WHEW!!!

Thank you all for the thoughts. Sorry it took me so long to respond. After looking pretty much everywhere and studying the fairly useless owner's manual, I decided it had to be one of the valves under the sink. I determined one valve was for the siphon hose so ruled it out. I chose the one farthest from the water heater and it happened to be the correct one.

Look in a storage bin close to the city water port. The valve may be on a side or back wall. They're usually located fairly close to the water inlet.

Not having a gravity fill is not really a rare design. There are some advantages and disadvantages to a separate fill port vs. a fill valve from the city water connection. (Less moving around of hoses with the combined port, for instance, and also the possibility of being able to pump water into the tank from a container using the winterize suction port if you have one.)

If you can't find information on the valves to use, it should not hurt anything to try various valves you've found out to see what they do. I would make sure the water heater is turned off before experimenting to prevent any possibility of firing it dry.

My guesses, and they're purely guesses, are that the valves underneath are low point and/or tank drains, and the three valves under the sink may be a water heater bypass, and the fill valve is someplace hidden in plain sight.

My Coachmen motorhome uses the city water port to fill the tank, but handily has all the valves for everything mounted on a sort of control panel in one of the outside compartments, along with a handy diagram for how to set them for various operations. About the only thing that could be greatly improved in my opinion is the labeling of some of the valves; the fill valve is one of two "operation valves," for instance.

RoyB wrote:
When all fails and you still haven't got a hold of someone that owns what you have you can contact the manf web page email and ask them. Be sure to pass along your trailer VIN number... My fresh water fill is gravity fill tube next to the front door on my Starcraft model trailer...


I went looking on-line with your year and model number asking internet how to fill your trailer and lots hits on google... Even a couple of dudes making U-TUBE videos pointing to this and that...

You should have learned all of that at the walk-thru where you bought the RV from...

Roy Ken

Thanks Roy, I may just have to contact KZ. The directions in the owner's manual should be clearer.

I didn't find any water fill videos for the KX MXT 303, but did find one that at least showed an example of the siphon/city water valve to divert water to the tank.

downtheroad wrote:
Or....look for something like this (the top one).

Unfortunately, there is not another fill valve on the outside. There are valves under the sink that you have to open/close to divert water to the freshwater tank. I was not familiar with such a design. Definitely something to put on my needs list for next RV.

Or....look for something like this (the top one).

When all fails and you still haven't got a hold of someone that owns what you have you can contact the manf web page email and ask them. Be sure to pass along your trailer VIN number... My fresh water fill is gravity fill tube next to the front door on my Starcraft model trailer...


I went looking on-line with your year and model number asking internet how to fill your trailer and lots hits on google... Even a couple of dudes making U-TUBE videos pointing to this and that...

You should have learned all of that at the walk-thru where you bought the RV from...

Roy Ken

LOOK on the out side of your trailer, for a round cover about the size of a large bottle cap. It most likely will be on the drivers side of your unit. Open it and look in and most times this is your filler .
If you purchased from a dealer he was irresponsible in showing you how to!
Gesh, post a picture. ok or try what kind of trailer is it?