Fresh Water Tank Overfilling

[Twotravelers]

Is it possible the check valve on the water pump can fail, causing the city water connection to fill the fresh water tank? We are hooked up to city water and our fresh tank is full. We try to empty that tank and it continues to read full. Same thing when we use the pump. Even a long shower, using the pump, leaves the fresh water tank reading full. For the last 2 days, during the afternoon heat, the overflow valve at the tank fill location has been spilling water out of the trailer, down the side of the airstream and onto the ground Hpw can this happen.

[kendrick.l.j]

Happens a lot. First, turn off the city connection completely or better disconnect. Turn water pump on and use the water in the Freash water tank until all gone. Then re connect with city water. Sometimes the check valve gets stuck. It isn't a real big problem and most of the time it will fix itself by turning on the Water Pump for a while. It may not happen again for months, other times it happens weekly.

[Twotravelers]

Thanks. We followed your advice and the problem seems to have been resolved, at least for now. Nothing unwanted is going into the fresh water tank.

[OTRA15]

Great news. If it happens again, just turn the pump on and off a few times, then hook up to city water and turn it on and off a few times, then the pump on and off few times. The grit usually dislodges itself.

To prevent grit from getting into your water system, you should always use an inline filter in the hose like this one:

https://www.amazon.com/Camco-40043-T...er+filter+hose

. . . whether you are filling the water tank OR using the hose for city water.

Although most folks consider it redundant, we also use an inline water pressure regulator like this.

https://www.amazon.com/Camco-40055-B...1WPXZFB5WRAFN7

Belts and suspenders . . .



Happy Trails!

Peter

[MelGoddard]

Originally Posted by OTRA15

Great news. If it happens again, just turn the pump on and off a few times, then hook up to city water and turn it on and off a few times, then the pump on and off few times. The grit usually dislodges itself.

To prevent grit from getting into your water system, you should always use an inline filter in the hose like this one:

https://www.amazon.com/Camco-40043-T...er+filter+hose

. . . whether you are filling the water tank OR using the hose for city water.

Although most folks consider it redundant, we also use an inline water pressure regulator like this.

https://www.amazon.com/Camco-40055-B...1WPXZFB5WRAFN7

Belts and suspenders . . .



Happy Trails!

Peter

I use a Valtera regulator, which is set at 50-55 psi. More flow to go.

[Lyman]

Well glad to see someone else has seem problem as me. Sometimes hook up to city water a few days at a time and fresh water gauge stays okay. Sometimes hook up to city water it will fill up fresh water tank to point it will over flo at fill up point.
Shut off city water run pump a while than back on city will usually be okay. This is fine as long as on sewer site. But if not you would fill holding tank pretty fast. So if not on sewer than just use tank drain than refill. So far if this is only problem I have I am a happy camper. I have 2017 Classic model.

[vintagemotor]

Originally Posted by MelGoddard

I use a Valtera regulator, which is set at 50-55 psi. More flow to go.

No need to use an external water pressure regulator as all AS have them built into the city water inlet.

[vintagemotor]

Originally Posted by Twotravelers

Is it possible the check valve on the water pump can fail, causing the city water connection to fill the fresh water tank? We are hooked up to city water and our fresh tank is full. We try to empty that tank and it continues to read full. Same thing when we use the pump. Even a long shower, using the pump, leaves the fresh water tank reading full. For the last 2 days, during the afternoon heat, the overflow valve at the tank fill location has been spilling water out of the trailer, down the side of the airstream and onto the ground Hpw can this happen.

Make sure that your water pump is OFF when connected to city water or it will fill the on board water tank and "leak" out of the overflow. I have even filled my on board tank from empty while at the RV park by leaving the pump on.

[Wazbro]

You could install a ball valve by the pump so this can't happen.

Only issue is then you need to remember the valve when you switch between city water and tank.

[OTRA15]

Originally Posted by vintagemotor

No need to use an external water pressure regulator as all AS have them built into the city water inlet.

True about the built-in water pressure regulators in modern day AS, but they have been known to fail, and let pressure surges reach the plumbing system.

No harm in using a belt and suspenders approach, per this earlier comment:

Originally Posted by OTRA15

. . .
Although most folks consider it redundant, we also use an inline water pressure regulator . . .
. . .
Belts and suspenders . . .
. . .

[OTRA15]

Originally Posted by vintagemotor

Make sure that your water pump is OFF when connected to city water or it will fill the on board water tank and "leak" out of the overflow. I have even filled my on board tank from empty while at the RV park by leaving the pump on.

In most AS, this would not be considered standard or normal IMO. With city water and pump on, the anti-back-flow check valve should still prevent water from back-flowing into the water tank. Some models may have intentionally offered this method for filling the tank, but most AS do not have it. [IMO]

Indeed, some AS owners manuals have specific instructions for turning the pump on, when the city water pressure is low, in order to get better flow for a shower etc..

Peter

[OTRA15]

Originally Posted by Wazbro

You could install a ball valve by the pump so this can't happen.

Only issue is then you need to remember the valve when you switch between city water and tank.

FYI in some models this would be a major pain in the neck, as the pump and filter area is quite inaccessible.

Preventing the failure of the check valve is the best medicine, by using an inline water filter to keep grit out of the check valve.

[james.mileur]

At my Camp Host gig in Utah, the DNR staff recommended a regulator at the hydrant to protect your hose from the sometimes 110+ psi water pressure.

[AnnArborBob]

Originally Posted by vintagemotor

No need to use an external water pressure regulator as all AS have them built into the city water inlet.

While this is true, not placing a pressure regulator at the point where the hose connects to the campground spigot leaves the hose vulnerable. We were once in a campground in Utah during a hot spell and a hose fitting explosively separated from the hose due to the increased pressure from the hot water. We've used a pressure regulator at the spigot ever since and have not had any issues. Plus the particular regulator we use has an easier mechanism for tightening and loosening the connection to the spigot which alone is a good reason to use it.

[OTRA15]

Great point, Bob, thanks!

Another semi-related suggestion is to turn off the city water hose bib when you go to bed at night. We had a fitting let go in the middle of the night, under the bed, and it was first of all very startling, and second of all very wet as it soaked the rug in the bedroom, and soaked everything stored under the bed, before we woke up, realized what was happening, and then stumbled out of the trailer in the middle of the night.



Yes, the downside is that you hear the pump come on when using the toilet, but . . . .

We also endeavor to turn off the city water when we leave the AS unattended, for similar reasons.

Peter

[MelGoddard]

Originally Posted by vintagemotor

No need to use an external water pressure regulator as all AS have them built into the city water inlet.

Until that 'plastic' gizmo breaks and pours water all over the place.'
Read some past posts.
I place my regulator at the water supply bib, to protect the hose
also.
AND, at our place in Blenheim, Ont. I measured line pressure at 70 PSI.
I believe that the AS regulator is set at 60-65(?)

[EdwardCharet]

My gut feeling is that, this has something to do with the wrong style check valve for the application. Thus the problem could be the application and not the check valve.
Leakage can happen from damage to the seat or disc or simple trash in the line in which case an elastomer is needed to provide zero leakage.
Check valves are flow sensitive and rely on the line fluid to open and close. The disc allows flow to pass forward, which opens the valve. Usually, check valve internals are flow sensitive so if there is not enough flow, disc movement occurs inside the valve since the disc is always in the flow path. This results in wear, potential for failure, and a higher pressure drop than calculated.
Some common types include: ball; dual plate or double-door; spring assisted in-line or nozzle or silent; piston or lift; and swing checks. Check with some plumbing contractors in toronto for more tips.

[Eagle & Bear]

The check valve the water pumps come with is a "duck bill type check valve". It will function correctly until the shore supply water pressure becomes less than 40psi. Without adequate pressure of 50psi or higher, the "duck bill" can open to allow water to flow backwards.

As stated above, the only way to stop the problem is to fill the fresh water tank, turn the shore supply off and use the pump until the water tank is emptied. Repeat the process when necessary. If anyone knows of a 12v water pump that does not have a duck bill valve please post a link to it.

[OTRA15]

Good recent points, thanks!