Newbie Fresh water tank fill question

PaulK · 04-28-2021, 02:03 PM

I bought my 2013 Sunset Trail 30RK last summer and never needed to use the fresh water tank. As we were preparing to go camping this year, I wanted to sanitize the fresh water tank. My expectation was that I would insert my hose into the fresh water tank inlet and it would just fill the tank. What I found was that after about 5 seconds the water started to backflow around the end of the hose. At first I thought that I may have had the water flow too high and overwhelmed the inlet line, but the same thing happened when I reduced the flow rate. Has anyone seen a problem like this? In all my camping I've always used city water and this is the first time I every tried using the fresh water tank. Could there be a valve on the inlet line that needs to be opened? I looked at the plumbing, and based on what I could see the valves into the pump were open, the valve to the antifreeze inlet hose was closed, and the valves for water into the hot water heater were open and the bypass line was shut. I didn't see any other valves. My fear is that a previous owner allowed something to get into the fresh water fill line that is blocking it.
I'd appreciate it if anyone has any ideas.

Thanks,

**Lloyd** · 04-28-2021, 02:27 PM

It's very possible the fill hose is kinked. How tough would it be to open the bottom in the area of the tank fill and check it?
Or maybe the vent tube is kinked or plugged.

PaulK · 04-28-2021, 02:33 PM

I'm reluctant to open up the cover underneath. I've never done it before. Can it be resealed easily?

**Lloyd** · 04-28-2021, 02:38 PM

Usually they are held on by a metal strip with self tapping screws. You don't have to remove the whole thing. Open it just enough so you can see in there to tell if there is problem.

**dagst1** · 04-28-2021, 03:57 PM

The fill hose will be 1 1/4 0r 1 1/2 in with no valves. One thing to check is the vent line for a clog. If you have access to an air compressor you can blow it out. If it is clogged it will "vent" thru the fill hose and bubble out.

One other thing are you sure that the tank is empty? Sometimes the check valve on the pump will leak back thru the pump and slowly fill the tank while you are on city water.

PaulK · 04-28-2021, 04:04 PM

I know the tank is empty because I opened the low level drain to make sure there was nothing in the tank. I will check to see how the bottom cover is attached. if it is screws, I'll open up the section below the fill cap to see what it looks like.
Is there a roof vent for the freshwater tank? I'll have to look more to see. I did try filling the tank with one of the cold faucets opened, but that didn't help.

**dagst1** · 04-28-2021, 04:21 PM

You say you opened the low level drain. You have a hot and cold low level drain and also a water tank drain. So if you opened all 3 you are good to go. The next step would be to check the fill hose from under the camper.

ugauga · 04-29-2021, 09:28 AM

Trying to fill it a bit at low flow rate while the low point drain from the tank is open may answer the question if the issue lays in the vent or inlet piping. Going directly with the hose is definitely not optimal, personally use and like this attachment. It does leave some place for air to escape, avoids the contact of the water with the very inlet that may be not too clean and makes the filling process generally straightforward and simple.

https://smile.amazon.com/dp/B0006IX850

Papa-T · 04-29-2021, 10:49 AM

I took a black washing machine hose with the female end. I cut off about 14” below that. It works well to attach to a regular hose and the smaller black hose will fit down into the fresh water fill hole and not jump out when you turn on the water.

PaulK · 04-30-2021, 09:08 AM

Thanks again to all the replies. The problem was that the fresh water tank was indeed full. No wonder it couldn't take more! I didn't know that there was a separate drain for the fresh water until dagst1 posted his note. When I found and opened that today, the water flowed and kept on flowing, so I assume that the tank was indeed full and that's why I couldn't add water. I feel like a dummy. Maybe there should be a book like "RV's for Dummies." The folks we bought the camper from said that they had never used the fresh water tank, so I assumed it must be empty.
As a newbie to a large trailer, this forum is invaluable for the benefit of all your experience. The manual is useless when it comes to details about the rig.
I hate to think that I've been hauling an extra 400+ pounds of water wherever I went.

divey · 04-30-2021, 09:35 AM

Everyone of us were newbie's and most of us are still learning things as we go. Glad you asked the question in the first place and found the answer/solution. The only stupid question is the one that isn't asked. With water sitting in the tank like that, best you sanitize your tank now. I use a cup of bleach mixed with 4 gallons of fresh water, pour it into the tank, then fill the tank with fresh water. Let it sit for a few hours, then run your taps till you can smell the chlorine at the tap. Drain the tank, refill with fresh water and drain again. I do that every year whether my tank has had water in it or not. Happy camping!

**mark5w** · 04-30-2021, 02:01 PM

Maybe there should be a book like "RV's for Dummies

Not to insult you but here ya go

https://www.abebooks.com/Complete-Id...waAnS1EALw_wcB

PaulK · 04-30-2021, 05:46 PM

Good price used on Amazon. It looks like it would be worth getting.

**dagst1** · 04-30-2021, 07:42 PM

Glad you figured it out. We all start somewhere and most of our wisdom came from our learning process. Been there done that.

egrum · 05-06-2021, 02:22 PM

Quote:

Originally Posted by PaulK

Thanks again to all the replies. The problem was that the fresh water tank was indeed full. No wonder it couldn't take more! I didn't know that there was a separate drain for the fresh water until dagst1 posted his note. When I found and opened that today, the water flowed and kept on flowing, so I assume that the tank was indeed full and that's why I couldn't add water. I feel like a dummy. Maybe there should be a book like "RV's for Dummies." The folks we bought the camper from said that they had never used the fresh water tank, so I assumed it must be empty.
As a newbie to a large trailer, this forum is invaluable for the benefit of all your experience. The manual is useless when it comes to details about the rig.
I hate to think that I've been hauling an extra 400+ pounds of water wherever I went.

So the question I am asking is: If the previous owner never used the water tank, and you have never used the tank, how did it fill? Also how long has the water been in the tank? The tank really needs some cleaning and bacteria killing now.
I would fill the tank about 1/2 way pour about 2 cups of bleach in the tank and go for a drive and try to sloosh the water around, then drain that water and refill with clean water, drive and sloosh again. Then drain, refill with clean water and let sit for a an hour or so drain again and then I would consider it good to go.
Just me 2-cents worth.

Good Luck

**dagst1** · 05-06-2021, 02:28 PM

The check valve in the water pump if it is bad would let water seep into the water tank over a long period of time. Eventually it would run out the overflow/vent.

toolman.dustin · 05-06-2021, 04:45 PM

Quote:

Originally Posted by dagst1

The check valve in the water pump if it is bad would let water seep into the water tank over a long period of time. Eventually it would run out the overflow/vent.

That's what happened to me last month. The fresh water pump check valve started leaking and when connected to city water the fresh water tank filled very slowly. I may have been hauling fresh water when I thought my tank was empty. Finally it overflowed. Swapping out the check valve was an easy 30 minute task.

wickey · 05-08-2021, 07:36 AM

Where exactly is the check valve and how did you repair it- is there a part or just cleaning? Don’t suppose you have a picture?

Russb · 05-08-2021, 07:41 AM

The check valve is built into the water pump. Kits are available for repair. Sometimes just running water thru the pump will clear the problem.

toolman.dustin · 05-08-2021, 08:46 AM

Quote:

Originally Posted by wickey

Where exactly is the check valve and how did you repair it- is there a part or just cleaning? Don’t suppose you have a picture?

You'll have to get the part number off your water pump. Then you'll be able to order a replacement check valve. Here's my data I looked up online. Not sure what you're make/model is, but your parts are available.

check valve:
https://www.rvplus.com/shurflo-model...94-800-03.html

water pump:
https://www.pentair.com/content/dam/...v/911-1008.pdf

data sheet:
https://www.pentair.com/content/dam/...08-101-X65.pdf

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