Connect ting City Water to Holding Tank

So I was thinking I'd like to add a valve which would allow me to allow city water to fill my holding tank while in a RV park. I filter at all parks and hookups and use park water to fill the holding tank sometimes anyway so having the ability to just open a valve instead of having to drag a hose around to fill the holding tank would be a time saver.

I can easily hook this up but thought I'd ask for experienced comment. Searching to find out if anyone else has done this I see a ton of forums of folks having this happen because of a system failure; ie the back flow valve in the pump failing. They all sound like this being done on purpose is a bad thing. Is it?

Every PC made in the past year or two have such a rotational valve.  The one installed in the beginning was very problematic.  I think it was a 4-position valve made of plastic.  The later (current day) 3-position valve is made of brass.  I am sure someone with a 2017 and 2018 model will reply with corrections to my inaccuracies.

The complexities of retrofitting an older PC with the same feature in the same manner would be challenging.  But a simple valve and extending the fresh water PEX line to the tank might be easy.  The challenge will be placing the valve in a convenient location.  Having the valve accessed from the outside via a small service door near the tank fill with overflow would be most convenient.  Positioned there will force you to monitor the filling process, closing the valve when the water spews out the tank vent.

Essentially, all you need is a couple of 'T' connectors, flexible (or hard) waterline and a quarter turn valve that bypass the water pump. 

That being said, I used to field test accessories for Pentair and had suggested they build their water pumps with that build in to their pumps.  Their answer was, they tried that once, and discovered that bypasses like that tended to leak.   The biggest problem being not shutting the bypass valve all the way.    Thus some water could still flow into the water tank and overfill it, and then leak inside the compartment where the water tank was.

Considering Pentair was a major manufacturer of water pumps and so forth, I took their advice and decided NOT to build one myself.

I would caution you to reconsider doing one yourself.

I plumbed and wired a ton of residential and commercial buildings in my day so I think I can figure out how to do this. I've already rummaged around in the utility compartment under the passenger side bed. I installed a solar charge controller and wiring in there and had to fix the water pump a few weeks ago when a corduroy road vibrated one of the power connectors in two. :-)

You're right a couple of tees and a valve should do the trick. I can use the existing winterizing hand hole under the mattress to reach in there and open the valve until it overflows the tank. Putting it in the exterior wall would be a classy install but not worth the effort I don't think.

Thanks for the assist folks!!

I think lifting the mattress to access a valve would be more of a hassle than simply attaching a hose to the outside filler. Your system is the same as I had on my 2010 pc , simple and problem free, I would prefer it to the 4 way valve on my 2014 pc. If it ain’t broke don’t fix it.

thrutraffic,

As I mentioned before, mounting the control valve via an outside access feature with lockable door, located near the gravity-fill tank vent, forces you to monitor and quickly close the valve when the tank is full.  I emphasis this for one reason, and it is not to save water.  My primary concern is that the first time you forget to shut off the inside-located valve, the vent for the tank cannot release water fast enough, causing a high water pressure condition in the fresh water tank.  Your low psi water lines or even the tank itself can easily rupture.

I assume that Phoenix with the current-day fancy valving has engineered things to prevent a pressurized fresh water tank condition.  All I know for certain is that our 2007 PC-2350 with such a valve located inside the rig combined with my ability to get distracted, I would do very serious damage to our PC.  Such an idea is great until you forget that first time.

You could remove the gravity fill cap to eject enough water fast enough to avoid a high water pressure condition, but don't forget to do so.

In my life time of 60 years, I have learned a lot about myself.  I find it best to keep "critical" things idiot-proof to prevent catastrophes.

Ron,
I call those RV moments, if you have been RV ing for long, I believe everyone will have them. They are hard to believe at the time, but they are reality. KISS is a great philosophy.
Doug

Thanks for the comments.

""having the ability to just open a valve instead of having to drag a hose around to fill the holding tank would be a time saver""

Might be interesting to see if it is... For filling our tank I have a small end that goes on the water hose and slips in the water fill opening. When we leave, if we need water in the tank, I merely unhook the hose from the coach (which I was doing anyway) find and attach hose fitting, then let it run until a) water flows out on the ground through the fill and vent or b) turn it off after sufficient water is added (usually ~10 gal for on road use, tying to keep that rear weight down). Either way, I do not have to supervise the process.

You are proposing going inside, reaching in and opening a valve, then monitoring it until it is full.  I agree with Ron, the vent hose may not flow enough to relieve pressure from this fill method. So just open the fill cap for a relief?

You could remove the gravity fill cap to eject enough water fast enough to avoid a high water pressure condition, but don't forget to do so.

So now the time difference is down to the time it takes to put on my hose attachment and walk around the back of the camper. And with the hose method, no danger of over pressure in the tank. And no adding plumbing and valve(s) to the system.

Charles Kettering was supposed to have said (regarding design), “Parts left off weigh nothing, cost nothing and don’t cause service problems.”  Was a sound observation in the 20's, and is today also.