Wednesday, February 20, 2013

Summer Mode/Winter Mode - Two Water Tanks in Roadtrek 190 and 210

One of the most frequent questions that comes up about Roadtrek's 190 and 210 models is about the two fresh water tanks that these models have. There is an interior tank that is located inside the van in the rear and there is the exterior tank which is located outside the van in the front. The exterior tank holds 14 gallons of fresh water. The interior tank holds 11 gallons of fresh water. Together the two tanks equal the capacity of the single 25 gallon tanks that are found in the other Roadtrek models. The questions that come up about these two tanks that confuses many are which tank is in use, how do I only have water coming from the rear tank, how come my back tank never empties and so on. The answer to all of these questions will be clear when you understand how the connections to these two tanks work. Detailed photos for the 210 are at the end of this article.

There are two valves inside the  Roadtrek that determines how water flows between these two tanks. In my Roadtrek they are located in the cabinet on the floor on the driver's side where the bed platform starts. Inside this cabinet you also find the water pump and the hot water tank with its bypass valves. Inside are also two valves that can shut off water flow to the outside shower. Here is the cabinet once opened -

The biggest thing in this photo is the hot water tank. If you look to the left you can just make out a red handle at the bottom. That is the location where you are going to find all that you need to control which tank your water flows from and how that works. 

Let me explain why there are two tanks. The Roadtrek 190 and the Roadtrek 210 is designed to allow one to travel in the winter with a fresh water tank inside the van where it can stay warm - provided that you have heat inside the van - and the water not freeze. To make this happen you set the tanks into what the Roadtrek manual calls "Winter Mode".  I will tell you how to set the valves for winter mode shortly. First, let's talk about what the Roadtrek manual calls "Summer Mode". Summer Mode is the normal operating mode to use all of the water that both tanks are carrying. 


Here are the two valves that control where and how the water flows from the two tanks - the small black handle valve on the  left and the large red handle valve on the right. The two valves in this photo are in SUMMER MODE position. Each valve is pointing along the length of the pipe that it is on. Here is a close up -

Take a look to the right of the red handle at the pipe that comes off with an elbow the right goes back and then is connected off to the right at the bottom. This pipe is going directly to the water pump.  The RED HANDLE VALVE is the TANK SELECTOR valve. The BLACK HANDLE VALVE is the FLOW THROUGH valve (Roadtrek calls this valve Tank Isolator Valve and also Tank Transfer Valve - two names in the manual for the same valve). Think of the valves as "red" and "black" because thinking of them with the names given only gets more confusing.

When the handles are set AS YOU SEE ABOVE the two tanks are in SUMMER MODE. Now, what does that mean. In Summer Mode water flows from the back interior tank into the front exterior tank and then from the front exterior tank into the water pump and then into your faucet or toilet or shower or hot water tank. In Summer Mode if you look at the monitor panel on the wall of your Roadtrek and push the test button you will see that the back tank or "FRESH 2" on the panel of LEDs will empty first, and after it is empty and you look at the monitor panel, you will start to see that the exterior tank or FRONT tank is then being used and emptying. As I said, in Summer Mode water is coming into the system from the FRONT tank - and while there is water in the back tank, the back tank water flows into the front tank and refills it. Confusing? A little. Water comes from the front tank but the front tank is filled back up from the back tank. With the valves set as above you do not have to do anything to use all of the water in both tanks. Some people say that they like to manually switch from one tank to the other. I am not sure why, but some do. I am not going to get into that and confuse you any more. If you want to just "automate" the process just put the two valves as shown here. WITH THE VALVES IN SUMMER MODE YOU HAVE THE TANK SELECTOR VALVE SET TO WATER COMING FROM THE EXTERIOR (FRONT) TANK AND THE WATER FLOW THROUGH VALVE IS SET TO ALLOW THE WATER TO FLOW FROM THE INTERIOR BACK TANK INTO THE EXTERIOR (FRONT TANK).



1 - It is getting cold outside. You are afraid of a sudden drop in temperature to below freezing and you don't want to take any chance that your water or pipes will freeze. This is one reason why you would put your water tanks into Winter Mode. (This is not a substitute for winterizing! This is temporary.)

2 - You are planning a winter trip and it will be freezing outside. The 190 and 210 are designed with the interior (back) tank to carry water inside a heated van. You want to use your interior tank for water. This is another reason why you would put your water tanks into Winter Mode.

Let me give you some warnings to be very clear up front. The interior of the van must be kept at 64 degrees F and above at all times - ALL TIMES - if it is freezing outside for the water in the back interior tank not to freeze. This means that you are going to run your furnace or a heater inside your van 24 hours a day while on your trip to keep the interior temperature at 64 degrees F or above. Once that water goes down the drain or the toilet into the waste tanks it is now again in danger of freezing and doing this requires that you add anti-freeze to your black and grey tank. At the end of your trip OR if you decide that you cannot keep your fan heated inside all of the time you are away - YOU MUST WINTERIZE to prevent your tanks, pipes and valves from freezing.  If you put your tanks in Winter Mode DRAIN your outside fresh water tank. Any water in there WILL freeze.

The valves are shown here in WINTER MODE. Here is a close up - 

The two valves now CROSS the pipes and are pointing to the front of the van. When the valves are set AS YOU SEE ABOVE your two tanks are in WINTER MODE. What is happening here is that you have now SHUT OFF ALL WATER COMING FROM THE EXTERIOR TANK and you have now CHANGED THE FLOW OF WATER COMING FROM THE INTERIOR TANK SO THAT IT NOW WILL FLOW DIRECTLY INTO THE WATER PUMP AND PIPES (and not your exterior tank) going off to your faucet or toilet or shower or hot water tank. Let's say that again - no water comes from the outside front tank. That tank is now shut off from the system. Water now comes from the inside back tank and goes into the water lines directly.

If we are traveling in the Fall we will fill the rear tank only and place the water system in Winter Mode. This way, if it gets cold at night, we have less of a chance that the whole water system will be effected by the cold. If we are in the Roadtrek and it is getting colder at night, we have the furnace or the heat pump on and the inside is heated. During the day it will go well above freezing and there will not be a problem. We did this once in a campground because we heard that the temperatures at night would go below freezing. It was over 50 during the day. We quickly drained the front tank and set the system to Winter Mode and we were fine.

If you are traveling in freezing weather with the system in Winter Mode, you do not have to be concerned about the hot water tank water freezing. This tank is inside your Roadtrek and is insulated with two inches of foam. There is only 15% surface of the tank not insulated and Roadtrek assures that it has been tested way below zero F and will be fine - as long as you have the cabin heated. 

Remember in WINTER MODE you need to keep the inside of the van heated. I cannot say that enough. There is no magic here. If the inside of the van goes below freezing the water in the system will freeze. AND water going into the waste tanks will freeze unless you add antifreeze to BOTH waste tanks. The waste tanks are OUTSIDE - whether there is heat on inside the van or not, if it is freezing outside and there is any water in either of the waste tanks, the water will freeze.

There is one other thing to be aware of if traveling in freezing weather in Winter Mode. There are two other valves that you need to shut off - the water valves on the pipes that come from the water system and go outside to the outside shower. Once you shut these two inside valves off, go outside to the shower faucet and open both handles to let any water in the faucet and pipes drain out - then close the outside shower handles. If it is freezing outside, the outside shower faucet and pipes will freeze if there is water in it. These two valves are located in this same compartment way in the back on the top at the van wall.


To keep all of this straight we made up small cards and attached them to the inside of the cabinet door. With the cards, we know at a glance which way the valves have to be for what. Each card on the opposite side has what happens when the valve handle is moved the other way. The cards are flipped when the valves are moved and are attached back down with "fun-tack" putty that holds them in place.


BLACK VALVE                 RED VALVE                                               RESULT

UP                                       UP                                      Summer Mode - Water from both tanks

ACROSS  (RIGHT)            ACROSS (RIGHT)            Winter Mode - Water ONLY from BACK

ACROSS (RIGHT)             UP                                      Water comes ONLY from FRONT tank

UP                                       ACROSS (RIGHT)             DO NOT DO THIS*

*Let me explain why Black UP and Red ACROSS will be a problem. Essentially you are sending water from the back tank into the front tank and the front tank is closed and not sending water into the system. Water will try to be drawn from the interior tank but the water there is flowing into the exterior tank while at the same time the pump is trying to draw water from the interior tank. Basically a mess. If this confuses you don't worry,  it confuses me too.


What happens when the RED handle is turned? 
You are selecting from which tank the water will be drawn into the water pump.


What happens when the BLACK handle is turned?
You are changing the flow of water from the interior tank either into the exterior tank or "isolating" the exterior tank from the system and allowing the water from the interior tank to flow directly into the water pump.


My back tank never empties. My front tank is working and is emptying. What is wrong?
The black valve is turned across the pipe and needs to be moved to the UP position. RED UP - BLACK UP


The water in my front tank is not being used. Water only comes from the back tank. What is wrong?
The system is in winter mode. Move the Red valve to the UP position.


No water is coming from any tank and I know the tanks are full. What is wrong?
Look at the valves - are the valves set to black up and red across - you have the setting that is shown as a problem in the chart above. Turn our black handle UP and your red handle UP. Water should then flow from both tanks as explained. IF it does not - there may be a clog in the pipes or a problem with the water pump. This may require a service technician to fix.


Which tank monitor lights correspond to which tank? 
Front exterior tank is FRESH 1.
Back interior tank is FRESH 2.


Hopefully, I have demystified Summer Mode and Winter Mode for you. I have to tell you that all of this confuses me also. I have had a lot of help from Meryl figuring this out. She is good at puzzles and she is the one who unlocked the mysteries of the two tanks. 

None of this applies if you have a Sprinter Roadtrek or a 170. These have only one water tank and there are none of the valves that I have been talking about. 

Thanks to one of our great readers, Nick,  I have been able to add to this article details about the location of the Summer/Winter Mode valves in the ROADTREK CHEVY 210 model.  Nick, was very gracious to respond to my request for him to take photos of the location of and the valves for summer/winter mode setting in his 210.  These photos are credited to Nick:

Here are the two cabinets past the kitchen cabinets in the 210 on the driver's side. In the cabinet closest to the front of the van, which is labeled "Cabinet A", is where you will find the valves - and the water pump - in the Roadtrek 210. 

The cabinet door pulls down to open:

And inside are the valves! 

The red handle valve and the small black valve are the same as in the 190 and will be set exactly the same as described in this article above!

(As an aside you can see the water pump filter on the right.)


  1. Well, you know how valuable this information has been to me! I've read it through thoroughly and understand it in its entirety now.

    You helped me so much on the road this winter - I could NOT figure it out using only the RT brochure. I'm printing this out and keeping in in the RT. Thanks again!

  2. Great Job!

    Wish I'd seen this six months ago when I tried to figure out how all this plumbing worked! :) Unfortunately, my rig (06C210V) is plumbed completely different than your pictures. It's also plumbed completely different than the RT manual shows. But, I played around enough to figure out. At least MOST of it.

    Do you have any idea what the deal is with the outside shower/valves? I've read in previous posts that RT says NEVER to mess with them ... leave them ON.

    I'm sitting in Elizabethtown, KY ... it's supposed to go to/below freezing, everything is taken care of BUT the outside shower valves. I've turned them OFF (handles across the lines) BUT the hot water still comes out "a little" and the cold is getting FULL Pressure when hooked up to the hydrant and pressure from the interior water pump when the hydrant is OFF.

    I've got antifreeze and can winterize if I must, although I likely won't bother since it's only supposed to go down to 32 for a couple hours, then warm up a bit. But, I've never been able to figure out what the #$%@ is the deal with those O/S shower valves.

    Any thoughts/ideas/advice greatly appreciated.

    Thanks! Bob Clark

    1. I have also been told by my dealer service never to touch the valves inside for the outside shower. I am covered because when I winterize I run antifreeze through the outside shower - both hot and cold, in addition to blowing those pipes out first with compressed air. I have been told that if the temperature does not go below 28 degrees for two days straight with day time temps going up well over freezing, then the pipes should be fine - but you always are taking a chance in freezing weather.

      Somewhere in your 210 you should have a valve arrangement similar to what I have shown in this article to change summer/winter mode - but I know that they were put in different places in different years. The basic operation principles should still be the same.

  3. Thanks Robert. That really was a great piece on the water system. Took a lot of time and I'm sure it will help many folks!

    My 210 is plumbed completely different than any or anything I've seen, BUT, you're right ... if you understand what they are trying to accomplish and a little basic plumbing ... you can figure it out by trial and error. Hot water, 2 tank system, ... is basically the same on all I would think. Took me a bit to figure out the city water, since "closing" the valve actually "opens" the flow to the RT. Not "normal, but I get it now. Your piece should go a long way to clearing up the mystery for most folks who buy from private owners and have to pretty much "learn as they go" as I did.

  4. Thanks a lot. You're very methodical, and this is useful for a slioghtly dislexic person like me!

  5. Excellent information. Thank you! I have a question about filling those tanks on my 210. RT says to only use the gravity fill on both tanks, never use city water to fill them. If I do, with the city water flow set very low, and the tanks in summer mode, will both tanks get filled?
    Or, if I fill the back tank, again in summer mode, will the front tank get filled also?

    1. I have found that when filling the tanks with city water the front tank gets filled. For the back tank to then fill, the water would need to back up from the front tank and then go into the back. It did not really work well when we tried it and we just gave up. If you have an earlier 210 than my 2011 190 the city water may not fill either tank - though I have seen city tank fill valve handles on earlier Roadtreks than mine - the valve handle used to be red. (Now it is black). This is right next to the city water connection. The first night that we had the Roadtrek we did not know about summer mode-winter mode and later found out that it was set to winter mode. That night we tried filling the tanks through city water and it filled and overflowed the rear interior tank -there is a overflow at the top of that tank that pours down outside near the rear tire. That night the front tank never filled at all unless we filled from the gravity fill in the front door. The next day back at the dealer we learned about summer mode/winter mode. (We had a very poor walkthrough the day we took delivery.) While some plumbing valves in the 210 are in different locations from the 190 - they are basically the same. I am not sure why RT would say not to fill your ? year 210 from city water.

      What we have also found is that the connection between the two tanks is slow running - so filling the back to fill the front also can take forever and not worth the effort. It is best to just fill from the two door gravity fill holes - I fill the front first and then move to the rear tank.

      When the water pump is running it pulls the water from the front and then the rear tank fills the front back up as it goes until the rear tank is empty. So on your monitor panel in summer mode you will see the back tank empty first.

      I am sure you know - never connect city water to the Roadtrek without a water pressure regulator connected to the hose anywhere before it connects into the Roadtrek - even if just filling the water tank THROUGH the city water connection.

  6. Haven't gone on trip yet... got our RT earlier this month and dewinterized with help of your instructions. Heard that to travel with less weight to only fill the exterior tank with water until you reach destination. If we do this, should the black isolator valve in the water system cabinet be in the vertical or perpendicular position to stop any water flow or leave it fully in summer mode position and just not fill back interiior tank?

    1. We travel all of the time with both tanks full. It has not made any difference in terms of mileage. If you want to only fill the front outside tank and not the back inside tank as you suggest, just leave the system in Summer Mode and fill the front tank and not the back. Water flows from the back tank into the front tank and from the front tank into the pump. If the black tank is empty it makes no difference in water flow - you just have that much less water. Once you get to where you are going just open the back tank fill in the door and fill the tank. In other words, the only thing the black tank does in summer mode is refill the front tank as the front tank's water flows into the pump. If you put the system in Winter Mode as described in this article, you take the front tank out of the system and are only using the back tank. This is good for when the temps outside are getting colder and you want to avoid the front outside tank from a freeze. If you want to shut the back tank off - see the chart above (black valve ACROSS the pipe to the right, red handle pointing UP (in line with the pipe) - but there is really no need to do this - just keep the back empty.

  7. Thank you... it is what we thought but wanted to make sure... so traveling with extra water weight in back tank doesn't make much of a difference in mileage - that surprises us! We really appreciate experienced RTers such as you.

    1. You are driving over three tons of van - another seven gallons of water is not that much added to the whole. Some travel with no water at all in the tanks and fill when they get to where they are going and this probably would make a difference. I like having the convenience of not having to stop and fill the tanks when we get to the campground - and also to have water in case we need to stop on the road and use the bathroom. Also on a weekend trip we generally don't have to use the campground water at all. Now, only filling the back and leaving the front empty may make a difference and in that case set to Winter Mode, fill the back, leave the front empty, and when you get to where you are going fill the front and reset to Summer Mode.

  8. Hello, can some one add some fidelity on how the valves coming from the top and bottom of the water heater are to be positioned? The first picture shows them pointed sideways but mine are pointed towards the aisle? Also what about the valve running between the top and bottom valves on the water heater. Is that supposed to be vertical or horizontal. I don't think this could have been made more confusing. Thanks for any help.

    1. We have several articles on the water heater and hot water tank - but here are the basics about the valve - point all valves toward the aisles - cold water flows into the water heater at the bottom and hot water flows out at the top to the sink. Top and bottom valves in that position are open. The valve on the pipe between them (vertical pipe) is closed. Put the three valves in the opposite positions and the water tank is now bipassed. No water flows into the hot water tank - top and bottom valves are closed and the middle valve is now open which allows the water to bypass the hot water tank and flow through to the sink. In the bipass setting, cold water will come out of the hot water faucet. You do this for winterizing so that RV antifreeze does not fill the hot water tank (6 gallons of it) when you are putting RV antifreeze into your pipes. There are other descriptions of this in our winterizing articles.

  9. I have RT 200 and will be taking it from NM to Ma. the day after Thanksgiving can I just winterize and not use the water? Do I need to get chains for the snow?

    1. If you are going to Massachusetts in late November you must winterize. We have an article about winter travel with no water and you should read that - Jan. 2014. As to chains - some states do not allow snow chains so you would need to check that for each state you will drive through, esp. Mass. Generally it should not snow that much unless you plan to stay into late December BUT how the weather patterns have been in the Northeast the past several years - you never know. What you do want to be aware of is if you drive on roads that are salted for ice, when you get back to NM put a garden sprinkler under the van and run it so that it washes off any salt that got on the bottom of the chassis. If you would like to discuss in any detail contact us by email with the link at the right side of the page.

  10. 2022 and your words are still helpful. Draining our new to us 2005 210. Thanks