Plumbing FW tank for FW refill?

[The_Breeze]

Most anyone who has their FW tank filler curbside and hooks street side, knows how inconvenient it can be to fill the FW tank.

Has anyone plumbed this to do refills while the RV is hooked up to the street side water supply and how did you do it? I can imagine it and asking if someone has already done this in order to get some additional insight.

Thanks.

[Bob Denman]

I think that Tiffin was thinking of you: when they installed their system.
The selections for those valves allow you to fill the freshwater tank; from you City Water source.
https://www.thorforums.com/forums/at...1&d=1595428425

[Beau388]

Originally Posted by The_Breeze

Most anyone who has their FW tank filler curbside and hooks street side, knows how inconvenient it can be to fill the FW tank.

Has anyone plumbed this to do refills while the RV is hooked up to the street side water supply and how did you do it? I can imagine it and asking if someone has already done this in order to get some additional insight.

Thanks.

Many have done it. You can search this forum for ideas. Basically you install a bypass for the water pump with a ball valve in the bypass line. If you are lazy like me, you can use an electrically activated valve such as used by yard sprinkler systems. The valve is activated by a guarded switch on the master control panel.

[GVP-The Boxcar Children]

Interesting that you raised this question, Breeze, as I was looking for the magic combination for our Aria on our last trip. Unfortunately our wet bay doesn't have an installed valving option to fill the FW tank from the host spigot (dumb). However, our FW tank drain resides in the wet bay too, is made of good sized PVC, and I'm considering adding a PVC female hose end to it. Then I can open the drain valve, then the spigot, and backfill the tank w/o dragging the hose around to the other side to do a gravity fill.
Just my "McGyver" possible solution.
GVP

[Wiley1]

Originally Posted by GVP-The Boxcar Children

I'm considering adding a PVC female hose end to it. Then I can open the drain valve, then the spigot, and backfill the tank w/o dragging the hose around to the other side to do a gravity fill.
GVP

My Class-C has the City Water connection and the FW fill port both on the driver's side of the coach. It is easy to disconnect the City Water and move the hose to the fill port when we break camp. Then you have to stand there and wait. Maybe you yell through the window to somebody inside who is watching the tank level gauge.

So, this thread doesn't exactly apply to my rig. But.....

I've often wondered why we fill our fresh water tank with a hose and the hose isn't securely attached to the fitting -- it just sort of lays in there. Maybe it falls out and maybe it doesn't. Is it because we don't want to force water into the FW tank under pressure? What would happen if the hose was securely attached to the fill opening and the tank became full? Definitely, water would shoot out of the little air vent hole. Then what? The tank splits a seam? A fitting breaks? A hose explodes? Or, everything holds the pressure nicely? I'm pretty sure I don't want to try it.

I've thought about adding a fill valve between the cold water system and the fresh water tank to allow filling the FW tank from inside the coach when connected to City Water. This seems safe to me if, and only if, I pull the front dinette cushion and watch the FW tank while it fills. For that reason, the fill valve should be located in that same compartment. In my opinion, it would be risky to locate it anywhere else.

Does anybody see a problem with my plan?
l

[Bnbl]

I have a 34J with all the plumbing under the bed. I added a bypass from the city water side of the pump and attached it to the winterizing port on the intake side of the pump. If you are ok with doing some pex plumbing this works really good. When the valve is open it backfills the FW tank.

[Wiley1]

Originally Posted by Bnbl

I added a bypass from the city water side of the pump and attached it to the winterizing port on the intake side of the pump. If you are ok with doing some pex plumbing this works really good. When the valve is open it backfills the FW tank.

My thought, exactly.

I'm sure you watch the tank carefully to make sure it doesn't overfill.

Have you wondered what might happen if the tank ever did accidentally overfill?

[paulwadley]

My 2018 Thor Siesta has the ability to fill the tank from the fresh water fill by switching the valve to tank. I do not have a gravity fed fresh water fill on it. The only way to fill my fresh water tank is to use the city water fill to tank.

Paul

[Wiley1]

Originally Posted by paulwadley

My 2018 Thor Siesta has the ability to fill the tank from the fresh water fill by switching the valve to tank. I do not have a gravity fed fresh water fill on it. The only way to fill my fresh water tank is to use the city water fill to tank.

That is interesting, informative, and good to know.

But, same question...
What would happen if you walked away with the valve open and that tank overfilled?

Just a stream of water spewing out of the air vent? or something worse?

[Bnbl]

Yes I watch the tank level while filling. Assume an overfill would run out of the external tank vent next to the external filler cap.

[paulwadley]

My valve stuck and I overfilled my fresh water tank over night. I had water coming out of the compartment where the tank is located. The water came out of the tank overfill vent on top of the tank.

Paul

[MLP]

Originally Posted by Wiley1

My Class-C has the City Water connection and the FW fill port both on the driver's side of the coach. It is easy to disconnect the City Water and move the hose to the fill port when we break camp. Then you have to stand there and wait. Maybe you yell through the window to somebody inside who is watching the tank level gauge.

So, this thread doesn't exactly apply to my rig. But.....

I've often wondered why we fill our fresh water tank with a hose and the hose isn't securely attached to the fitting -- it just sort of lays in there. Maybe it falls out and maybe it doesn't. Is it because we don't want to force water into the FW tank under pressure? What would happen if the hose was securely attached to the fill opening and the tank became full? Definitely, water would shoot out of the little air vent hole. Then what? The tank splits a seam? A fitting breaks? A hose explodes? Or, everything holds the pressure nicely? I'm pretty sure I don't want to try it.

I've thought about adding a fill valve between the cold water system and the fresh water tank to allow filling the FW tank from inside the coach when connected to City Water. This seems safe to me if, and only if, I pull the front dinette cushion and watch the FW tank while it fills. For that reason, the fill valve should be located in that same compartment. In my opinion, it would be risky to locate it anywhere else.

Does anybody see a problem with my plan?
l

If you know the size of your tank, get a flow meter. They are quit accurate and I use it to fill my fresh water tank.



https://www.amazon.com/Save-a-Drop-P...s%2C238&sr=8-3

[bojanlora]

Originally Posted by Bnbl

I have a 34J with all the plumbing under the bed. I added a bypass from the city water side of the pump and attached it to the winterizing port on the intake side of the pump. If you are ok with doing some pex plumbing this works really good. When the valve is open it backfills the FW tank.

Attachment 25229

Attachment 25230

Great idea. I think I will do the same but I'll use this valve and wire the switch by the inverter control by entrance where I can watch the tank level.

https://www.amazon.com/dp/B018WRJYUE/

[Wiley1]

Originally Posted by paulwadley

My valve stuck and I overfilled my fresh water tank over night. I had water coming out of the compartment where the tank is located. The water came out of the tank overfill vent on top of the tank.

Are you saying the water overflowed into the living area?

My tank has small (1/4"?) tube leading to the outside world to vent air.
Works great unless a mud wasp clogs it up.

I'm hoping, if I ever overfill my tank, that all the plumbing will hold and some of the pressure will be relieved by water squirting 6-15 feet out away from the coach.

[Wiley1]

Originally Posted by Bnbl

I added a bypass from the city water side of the pump and attached it to the winterizing port on the intake side of the pump. If you are ok with doing some pex plumbing this works really good. When the valve is open it backfills the FW tank.

I really want to do what you did, except:
My water tank is under the forward dinette seat but the water pump is under the aft dinette seat. The line from the tank to the pump runs under a 45 degree kick-plate, under the dinette table.

The aft compartment is stuffed with the gigantic Aims 2500W inverter that I added, so there isn't much room to operate. Even if I could somehow squeeze my hand in there, I would not be able to see the tank to know when it nearly full.

I guess I could run a second water line under the kick-place. That would allow me to put the bypass valve in the same compartment with the water tank, where it belongs. During the fill process, my face would be a few inches from the tank so there should be no surprises.

I hesitate for two reasons:

1. I don't know if there is enough room under that kickplate for a second hose.
2. An additional hose adds several new points of potential failure and makes winterization slightly more complicated.

Maybe shoving a hose into a hole on the side of my camper isn't so bad after all.

[16ACE27]

Originally Posted by Wiley1

Are you saying the water overflowed into the living area?

My tank has small (1/4"?) tube leading to the outside world to vent air.
Works great unless a mud wasp clogs it up.

I'm hoping, if I ever overfill my tank, that all the plumbing will hold and some of the pressure will be relieved by water squirting 6-15 feet out away from the coach.

It will start that way, but that vent cannot keep up with the full flow of the input and eventually that tank will expand and probably rupture.

[Wiley1]

After reading this thread, I decided that I would like to install a pump bypass valve for fresh water tank fill. But, when I installed my inverter under the rear dinette seat, the pump and and strainer became nearly inaccessible. That was OK until the strainer clogged with debris left in the fw tank by Thor and the pump went dry.

After pulling the inverter out to get access to the pump and strainer, I decided that I never wanted to do that again. Besides, do we really want a water pump in the same compartment as the breaker panel, fuse panel, converter, ATS, and inverter?

Fortunately, Thor wasted a ton of space under the front dinette seat, more than enough to hold the water pump, strainer, and any mods that I want to make.

What I did:
1. Removed the pump and strainer from under the rear dinette seat.
2. Connected those two water lines together.
3. Extended the pump power wires to the front dinette seat compartment.
4. Cut a piece a piece of plywood and mounted it on rubber furniture feet, 1/4" above the water tank.
5. Mounted the water pump and strainer on the plywood. Connected the extended power cable.
6. Installed a pump bypass pipe with cutoff valve. This allow the fresh water tank to be back-filled from City Water, just by turning the knob.
7. Installed a shutoff valve after the water pump. If the pump needs to be removed, City Water can still operate.

What I learned:
1. I'm too cheap to pay $50 for a PEX crimping tool.
2. A 5/8" hose clamp isn't strong enough. It will break before it seals.
3. A 7/8" hose clamp will work, but it is tricky. It will leak if not tight enough. It will break if too tight.
4. Brass tees and elbows seal better than those made of plastic.
5. Thor uses cheap components everywhere.
6. Thor factory people do shoddy work.
7. A water pump is better at blowing than sucking.
8. A water pump works better when it is nearer to the water source.
9. The pump might be a little noisier in its new location, but just slightly.

Benefits:
1. It is nice to be able to fill the fresh water tank without leaving the coach.
2. The next time I go to clean the water strainer, I won't need to remove the inverter first.
3. If the pump or strainer springs a leak, my electrical components won't get wet.

Pictures, BEFORE and AFTER: