Gravity Feed?

[SCPOSWRET]

Just for my own understanding. Why is the FW tank called "Gravity Feed"? Originally it sounded like one would just put the hose in the opening and
turn on the water and it would feed the tank via Gravity, however, I've spent HOURS figuring out how to ACTUALLY get the water in without risk and
without jacking around all day, reading 100 different articles, etc, etc, to finally learning how to get the D... FW water into the tank. So...............
why is it referred to as a "Gravity" type fill system when it clearly is not? Just want to understand. All experiences, suggestions, tips, and comments
appreciated.

 

[Silverado23]

The photo is a reference and can vary but the details should be similar.


The gravity water fill uses port similar to pictured connected to a large fill hose and a smaller vent hose.
Water is added through the large hose and air is released from the tank as water replaces it.

Water may not fill the tank properly if the hoses are routed poorly, kinked or blocked as air cannot be released and then water cannot freely flow into the tank. the end result may be water spraying back out the fill port. overfilling can also release water in the same manner.

It is important that the vent hose is routed so that water cannot fill the hose or become blocked with overflow water should the tank be over filled.

The main fill hose should be routed so that water drains freely into the tank and does not pool into the hose.


Usually the Fill port is located above the floor and the storage tank below the floor.
if filling is difficult and your sure the vent is clear of debris, then The hoses should be inspected and rerouted to remove sag and allow water to drain out of the hose.

 

[danemayer]

It's a gravity fill because the entry point for your water hose is higher than where the other end connects to the tank. Gravity carries the water into the tank. The hose is supposed to loosely fit into the entry.

The other type of fill uses water coming out of the hose under pressure. On the traditional gravity fill arrangement, the tank has no overflow, just an air vent. If you jam the hose into the fitting tightly, and force water in under pressure, when the tank gets full it may rupture.

However, many of today's fresh tanks now have overflow fittings that extend outside the frame, terminating in a 90 degree Pex fitting. If you have these, it's less likely you would damage the tank by overfilling.

 

[SCPOSWRET]

It's a gravity fill because the entry point for your water hose is higher than where the other end connects to the tank. Gravity carries the water into the tank. The hose is supposed to loosely fit into the entry.

The other type of fill uses water coming out of the hose under pressure. On the traditional gravity fill arrangement, the tank has no overflow, just an air vent. If you jam the hose into the fitting tightly, and force water in under pressure, when the tank gets full it may rupture.

However, many of today's fresh tanks now have overflow fittings that extend outside the frame, terminating in a 90 degree Pex fitting. If you have these, it's less likely you would damage the tank by overfilling.

thank you Dan, appreciate the clarification.

- - - Updated - - -

The photo is a reference and can vary but the details should be similar.
View attachment 57936

The gravity water fill uses port similar to pictured connected to a large fill hose and a smaller vent hose.
Water is added through the large hose and air is released from the tank as water replaces it.

Water may not fill the tank properly if the hoses are routed poorly, kinked or blocked as air cannot be released and then water cannot freely flow into the tank. the end result may be water spraying back out the fill port. overfilling can also release water in the same manner.

It is important that the vent hose is routed so that water cannot fill the hose or become blocked with overflow water should the tank be over filled.

The main fill hose should be routed so that water drains freely into the tank and does not pool into the hose.


Usually the Fill port is located above the floor and the storage tank below the floor.
if filling is difficult and your sure the vent is clear of debris, then The hoses should be inspected and rerouted to remove sag and allow water to drain out of the hose.

thank you Silverado

 

[avvidclif]

Take an old piece of water hose with the faucet end on it. Cut it abt 2-3' long. Put it on the end of your hose and stick it a foot or so into the fill nozzle. That will be far enough get past the vent line and you can crank up the water. When it overflows the tanks full..

 

[SCPOSWRET]

Take an old piece of water hose with the faucet end on it. Cut it abt 2-3' long. Put it on the end of your hose and stick it a foot or so into the fill nozzle. That will be far enough get past the vent line and you can crank up the water. When it overflows the tanks full..

thank you Cliff, I tired this same procedure with a recommended 16” piece of hose and it worked only if I pushed the brass male end up against the black plastic housing of the inlet. Only then did the water not back up (much at all), however, I had to keep pressing hard the entire time or if I let off, the water would return. I suspect this is the ‘pressurized’ situation I’ve been advised about. I stopped at 2/3 full which is fine for now.

Maybe the hose length I used was too short to get far enough down to work as well as you described, but thank you for the tip. Happy camping.

 

[Silverado23]

thank you Cliff, I tired this same procedure with a recommended 16” piece of hose and it worked only if I pushed the brass male end up against the black plastic housing of the inlet. Only then did the water not back up (much at all), however, I had to keep pressing hard the entire time or if I let off, the water would return. I suspect this is the ‘pressurized’ situation I’ve been advised about. I stopped at 2/3 full which is fine for now.

Maybe the hose length I used was too short to get far enough down to work as well as you described, but thank you for the tip. Happy camping.

It definitely sounds like your vent is kinked or blocked.
From the photos and layout of your RL250, Your water fill is probably located under the kitchen sink.
You may want to make sure you don't have a kink or other obstruction in your hose lines.

A longer hose can help but you also risk pulling the fill hose from the back of the port fitting. It should fill with ease.

 

[SCPOSWRET]

It definitely sounds like your vent is kinked or blocked.
From the photos and layout of your RL250, Your water fill is probably located under the kitchen sink.
You may want to make sure you don't have a kink or other obstruction in your hose lines.

A longer hose can help but you also risk pulling the fill hose from the back of the port fitting. It should fill with ease.

Thank you. I’ll check under the kitchen sink tomorrow to see what I can see. Will advise. Thanks again Silverado.

 

[hoefler]

Or, you can install a Tee fitting behind the city hook up line and another Tee in the supply line to the water pump from the tank. Connect the 2 Tee's together with a valve in between that can be conveintly reached. That is what I did, now I can fill my tank at full line pressure without and issues.

 

[jerryjay11]

Or, you can install a Tee fitting behind the city hook up line and another Tee in the supply line to the water pump from the tank. Connect the 2 Tee's together with a valve in between that can be conveintly reached. That is what I did, now I can fill my tank at full line pressure without and issues.

I wouldn't modify anything. As I have said before I have the same TT and have no problem filling my tank. I use a "clean" washing machine hose that I have beveled cut to aid it entering the fill hose, all the way to the tank. I can fill my tank right to the brim with no backflow until the tank is full. If I didn't use this fill hose, yes it would back up under house pressure. I have used this method for several years and several campers with no problems. As a matter of fact Camco sells a tank filler, but I didn't care for the shorter fill hose.

My fill hose is 24" long and I can get it around any bend in the TT fill hose right to the top of the fresh water tank. I know because I can hear the initial flow of water hitting the bottom of the plastic fresh water tank.

 

[Silverado23]

I wouldn't modify anything. As I have said before I have the same TT and have no problem filling my tank. I use a "clean" washing machine hose that I have beveled cut to aid it entering the fill hose, all the way to the tank. I can fill my tank right to the brim with no backflow until the tank is full. If I didn't use this fill hose, yes it would back up under house pressure. I have used this method for several years and several campers with no problems. As a matter of fact Camco sells a tank filler, but I didn't care for the shorter fill hose.

My fill hose is 24" long and I can get it around any bend in the TT fill hose right to the top of the fresh water tank. I know because I can hear the initial flow of water hitting the bottom of the plastic fresh water tank.

I agree, There is no reason to add a tee. Even a short fill hose should work fine, if your installed hoses are routed correctly.(No kinks, or sags especially in the vent line)

 

[jerryjay11]

I agree, There is no reason to add a tee. Even a short fill hose should work fine, if your installed hoses are routed correctly.(No kinks, or sags especially in the vent line)

And if that were the case it should be taken back to the dealer for correction. Not unnecessarily modified.

 

[SCPOSWRET]

I wouldn't modify anything. As I have said before I have the same TT and have no problem filling my tank. I use a "clean" washing machine hose that I have beveled cut to aid it entering the fill hose, all the way to the tank. I can fill my tank right to the brim with no backflow until the tank is full. If I didn't use this fill hose, yes it would back up under house pressure. I have used this method for several years and several campers with no problems. As a matter of fact Camco sells a tank filler, but I didn't care for the shorter fill hose.

My fill hose is 24" long and I can get it around any bend in the TT fill hose right to the top of the fresh water tank. I know because I can hear the initial flow of water hitting the bottom of the plastic fresh water tank.

Thanks again Jerry, I'm thinking that it may be just as easy to stand on a small ladder with a long neck funnel and pour it in.

 

[jerryjay11]

Thanks again Jerry, I'm thinking that it may be just as easy to stand on a small ladder with a long neck funnel and pour it in.

Well if you feel like standing there holding a funnel and hose, have at it. It will probably take 4 times as long since a funnel is going to do the same thing as been happening.

 

[SCPOSWRET]

Thank you. I’ll check under the kitchen sink tomorrow to see what I can see. Will advise. Thanks again Silverado.

Silverado: inspected below the sink as you recommended. didn’t see any kinks or anything else that would cause me concern except one hose that, as others, has an inline valve, but this one is in the off position (turned perpendicular to the hose) but since I have no idea what this hose does, maybe it’s supposed to be that way (?).

tomorrow I’ll try again using the recommended black washing machine hose section about 24” long and let you know if it works. Ive traveled about 500 miles since the original report of water backing up when trying to fill the FW tank so just maybe (as some mechanical things do) it will now work without a logical mechanical explaination. I’ll report back. Thank you again for your tips.