Water System

[BillyBoy]

I'm new to RVing, and also with my 2015 Grand Tour. I need a little help to understand the water system. When I hook up to campsite water, how does the system work?
>Am I still drawing down the fresh water tanks?
>Is there some sort of bypass which senses hook-up pressure, and switches over the feed from the tank?
>If I forget to turn off the pump, and then hook up, what happens? Am I on hook-up, or tank supply?
I am asking because I would like to cycle through the tank water whenever possible. I usually hook up, and so the tank may not be used for weeks at a time. Personally, I don't like the flavor of plastic.....

[Protagonist]

Originally Posted by BillyBoy

When I hook up to campsite water, how does the system work?
>Am I still drawing down the fresh water tanks?
>Is there some sort of bypass which senses hook-up pressure, and switches over the feed from the tank?
>If I forget to turn off the pump, and then hook up, what happens? Am I on hook-up, or tank supply?

There are two ways to use your fresh water system.
1 - Hook up to municipal water. This does NOT fill the freshwater tank; there is a check valve in the pump to prevent back-flow from the plumbing to the tank. In this situation, you don't even turn on the pump.
2 - Fill the freshwater tank. This requires you to turn on the pump. The pump has a pressure switch, that senses a drop in pressure whenever you open a faucet, and turns on the pump.

There is no need to do both at once. If you've been using the freshwater tank and you forget to turn off the pump when you hook up to municipal water, nothing happens. There's enough water pressure from your municipal source to keep the pump from activating, and you're using municipal water only.

Personally, I don't like the flavor of plastic.....

The fresh water tank is made of food-grade plastic that meets ASME and US FDA standards. One feature of food-grade plastics is that they don't impart any taste to the water. You only taste plastic when drinking from food-grade plastic if your lips or tongue come into direct contact with the plastic. Which doesn't happen with your freshwater tank unless you crawl underneath and kiss the tank.

[SteveH]

Think of the water system as one system with two feeds. One thru the pump from the tank, and the other from the campsite water input.

The pump is controlled by a pressure switch that senses low pressure to turn it on, high pressure to turn it off. If you have the switch on, and the campground is on, provided the campground pressure is high enough to keep the switch in the off position, nothing happens with the pump.

However, all the Airstream trailers I have had, have a pressure regulator on the water input from the campground, and so if the pump is on at the same time, the pump will also run when you turn on the water.

If you are concerned about the tank water being in there too long, you can always drain it after every trip, a good idea IMHO.

[BillyBoy]

Thanks to all who responded. I think I understand it now.....

[Bruce B]

Originally Posted by Protagonist

...One feature of food-grade plastics is that they don't impart any taste to the water. You only taste plastic when drinking from food-grade plastic if your lips or tongue come into direct contact with the plastic. Which doesn't happen with your freshwater tank unless you crawl underneath and kiss the tank.

I learn the most interesting things here!
Thank you!
Bruce

[BillyBoy]

Whoops. I just found something else I don't understand.
I am frantically trying to winterize my new Grand Tour, because there's cold weather predicted and I won't be around to check in the storage yard. So, I figured out most of what I need to do, but here are two questions:
>This is a new layout, so the manual is only about 15% accurate. There are two 1/4 turn valves accessible through a door at the floor under the fridge/freezer stack. One looks like it's in the hot water line, and the other is in the cold. The thing is they both appear to be in the closed position (handle perpendicular to the line). What can they be? If they were normally open, I could understand that they are shut-offs, but they appear to be closed, and still everything worked normally in my last trips.
>If I open the bypass valve on the heater, does this take the heater tank out of the line? I would like to pour anti-freeze into the fresh tank and then run the pump to bring it into the plumbing, but I hate to waste 6 gallons in the heater tank (which I just drained, so it's OK for cold).
Thanks to all who are helping me. I've called Airstream several times, but voicemail can't get answers the way these forums can.

[Protagonist]

Originally Posted by BillyBoy

>This is a new layout, so the manual is only about 15% accurate. There are two 1/4 turn valves accessible through a door at the floor under the fridge/freezer stack. One looks like it's in the hot water line, and the other is in the cold. The thing is they both appear to be in the closed position (handle perpendicular to the line). What can they be?

Low point drains. Open them (and open the faucets) to drain any water trapped between pump and faucets. There may be another set on the opposite side of the van as well. Close them again before pumping antifreeze.

If I open the bypass valve on the heater, does this take the heater tank out of the line? I would like to pour anti-freeze into the fresh tank and then run the pump to bring it into the plumbing, but I hate to waste 6 gallons in the heater tank (which I just drained, so it's OK for cold).

Yes, the bypass does exactly that; it bypasses the water heater.

[PSchw]

But don't forget to get your plug out of the water heater to empty the water heater tank.


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[BillyBoy]

Thanks to all this good info, the job's done. Still don't know what those two valves under the fridge are there for, but I've got pink stuff coming out all over. I wonder: the label says it's for use in potable water systems, but then it says it's toxic if ingested. I'll let you know when I next use the tank. If I'm not back in these forums, you'll know what happened.
Now all I need to figure out is what that second battery under the hood is for. I found the starter battery under the driver's seat, but that second one defies explanation.

[SteveH]

I don't know for sure, but I would suspect the second battery is the "house" battery for the camper.

[PSchw]

There us a MB option for a second batterie this would be installed under hood on the driver side.
The 2 valves are the low point train valves. There are installed on the lowest point if the system so you can train it completely. If you used antifreeze you should be good it is more for people they don't want antifreeze in there water system.
If you de-winterize you need yo flush your system real well to get the antifreeze out.
The stuff should not kill you but is not healthy either I heard it as a bad taste too therefore flushing is important.
That is the reason I am not using it and just empty the system and blow it out .



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[Protagonist]

Originally Posted by SteveH

I don't know for sure, but I would suspect the second battery is the "house" battery for the camper.

Actually, no. The house batteries are tucked up under the rear of the van. The battery under the hood is an "accessory" battery, which may not actually be used for anything in this case. It's provided as an option on Sprinter vans for upfitters to use for powering things that have to remain powered when the engine is shut off. Some model years of Interstates have it; some don't.

[gambita]

The 2 valves under the fridge , 1 red and 1 white are use to direct flow of water coming from the city water.
If the valve is in the "T " position water source is from the Tank.
If you open it up your water source will be city water.
I stand to be corrected

[Protagonist]

Originally Posted by gambita

The 2 valves under the fridge , 1 red and 1 white are use to direct flow of water coming from the city water.
If the valve is in the "T " position water source is from the Tank.
If you open it up your water source will be city water.
I stand to be corrected

Then why are there two, one for hot and one for cold? All water coming from the tank OR the municipal service is cold.

I stand by my assertion that they're low point drains, just like every model of Interstate has, although the locations will differ based on floor plan.

[gambita]

Water line under the sink in our 2015 interstate xl

[gambita]

The us also water valves at the wheel well position covered by a cup holder. This valves control water going to the shower

[gambita]

Is there a way you can upload video here ? I recorded the service manager demo about this.

[PSchw]

Yes the same as on my 2013 Interstate. Low point drains on both sides one for cold and one for hot water line.


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[gambita]

Im confused niw :-(
Whats the use of low point drain?
How will you switch water source from tank to city water?

[BillyBoy]

I don't think they're low point valves, because the plumbing seems to either be level or rise from there. I'll try opening them and see if any mystery liquid appears somewhere. As for that second battery under the hood, protagonist is correct, because I learned a few days ago that the house batteries (2) are tucked under the coach driver's side aft of the wheel well. And standing on end, by the way. What's puzzling is that the battery under the hood is fully connected into the system with a substantial gauge conductor, so it's doing something. Maybe I'll just pull the connection and see what goes dark.