fresh water system assistance

cygvan · 04-15-2012, 05:54 PM

Hi all,

starting to piece together my fresh water system. i can use some help o be sure i am on the right path. search function was too broad when using "water system". google returns are all over the place.

so far, i have come up with the following:

fresh water tank (15-20 gallon size).
fitting on bottom of tank with ball valve ----> goes to water pump
water pump, shurflo 12v. ------> goes to "manifold" or splitter (need help on this)
manifold splits supply to cold water valve on sink faucet and hot water heater inlet.
hot water heater will be small 4 gallon electric tank (this type and model works for my application)----->hot water then goes to hot water valve on sink faucet.

the fresh water tank will have a vent located near the top to equalize pressure when filling

the fresh water tank will have a fitting that leads to a fill port installed on the side wall of the van.

i plan to use hose connections (good quality) from the fill port to the fill fitting on the tank so that i can install an inline filter to clean the water before it enters my tank. my water supply is very high pressure and the flow is high.

i will have on-hand, a pressure reducer (connects to hose) and the water filter mentioned above allows for a flow of 5gpm.

although my parking arrangement includes a water connection, i will not be connected to in all the time like a city water connection. i will connect only to fill.

my questions are as follows:

do i need some sort of check valve to ensure that the water supply going into the heater does not back up into the system? something between the "manifold" and the heater?

i plan on using pex for everything other than the "fill side"...any suggestions? i know there are a few types of pex fittings. i prefer one that does not require a billion dollar tool.

i plan on using brass valves and i picture the "manifold" being brass as well. if i can avoid soldering i will. but i am comfortable with light soldering of copper. dont have anything hot enough for brass around like mapp gas or whatever it is.

on the waste side..i already have a design for that.

any help on the supply side would be grateful...i feel like i am missing something.

thanks

joey2cool · 04-16-2012, 01:13 PM

My system has no hot water heater, but the only place I have a check valve installed is internal to the Shurflow pump (don't want the impellers going in the reverse direction). You didn't mention the city water hookup - there's a built-in pressure regulator that comes with the fitting I have.

cygvan · 04-16-2012, 02:25 PM

Quote:

Originally Posted by joey2cool

My system has no hot water heater, but the only place I have a check valve installed is internal to the Shurflow pump (don't want the impellers going in the reverse direction). You didn't mention the city water hookup - there's a built-in pressure regulator that comes with the fitting I have.

not sure which style hookup i will use. city or gravity. seems like i could use either one. good to know that some of the city versions have the regulator.

which model shurflo are you using if you dont mind me asking?

joey2cool · 04-24-2012, 01:06 PM

The make and model is ShurFlow 183-029-14 City Water Entry with Check Valve.

dhally · 04-24-2012, 02:19 PM

I have some experience using these systems but have never built one. I do have lots of experience with plumbing and piping in general. Here's my take.

I see you live in NJ so freezing could be/will be an issue. 2 methods to prevent freezing: either drain entire system or fill it with RV antifreeze. It may be difficult to arrange the tubing so it can all completely drain, so the antifreeze may be the best option.

A slick system for antifreeze is to install a 3-way valve between the tank and pump, plus a tank drain valve. The 3rd port on the 3-way valve has a short tube that can be inserted into a gallon of RV antifreeze. Procedure: drain the tank, turn the 3 way valve, insert tube in jug, then run the pump and open each hot and cold water valve in the system until the water turns pink.

The hot water heater is especially prone to freezing. You can install a bypass around the water heater using three way valves. For freeze protection, bypass the water heater and drain the water heater. Then when the RV antifreeze in put in, it doesn't get into the hot water tank but can fill the hot water piping.

Manifold splitter
If there are just 2 cold water connections, a tee fitting should work fine. A brass fitting would probably require threaded adapters to Pex, which might end up using more space and having more leak potential than just using Pex tees.

Check valve
No check valve is needed at the inlet to the water heater. Just make sure the tubing connecting to the heater is rated for hot water. The cold water connection is at the bottom and hot water rises so no problemo. If you have a city water connection, then a check valve is required at the pump discharge to prevent city water from flowing backwards through the pump into the tank.

Pex fittings
I've never used Pex but I have used compression type fittings. The most important thing is to not have leaks. If that requires a tool it might be a good investment.

Other ideas
- The water filter could be connected on the hose on the outside of the van. This could save space and make changing the filter easier.
- Consider how the fresh water tank will be cleaned out. Even with a filter it can get skanky.
- Consider adding an outside shower! If I were investing in a hot water heater I know I would...
- Consider adding a city water inlet. If you have city water available, or camp at RV parks, it is much more convenient than filling and cleaning the tank. It would only add a check valve, tee, and inlet fitting.

witoke · 04-24-2012, 06:17 PM

I think a back flow preventer valve is probably a good idea just to forestall any problems with the heater cycling on to maintain water temperature and to be cautious in case water will sit in the heater for long periods between uses. But remember it will mean the heater will not drain automatically so unless you add a drain valve on the heater loop you'll have water sitting in there.

Pex tools are now really quite reasonable, last one I bought with the adaptors was about $40 at one of the big box stores. They are so quick and easy to use, it will save hours over conventional plumbing and the system is very reliable. It does have a fair amount of forgiveness to freezing as well since the tubing is flexible. I introduced it to a plumber friend of mine who thought that the tools were still very expensive. He won't use anything else now unless someone requests copper.

And just FYI, unless you need shower/irrigation level water pressure, the Shurflos are a bit of overkill. You can get a small in-tank pump like this:

<http://www.busdepot.com/details.jsp?partnumber=255070805>

that is more than adequate for a faucet flow and is a lot cheaper. The last one I had in my Westfalia lasted 28 years....

cygvan · 04-25-2012, 04:48 PM

Quote:

Originally Posted by dhally

I have some experience using these systems but have never built one. I do have lots of experience with plumbing and piping in general. Here's my take.

I see you live in NJ so freezing could be/will be an issue. 2 methods to prevent freezing: either drain entire system or fill it with RV antifreeze. It may be difficult to arrange the tubing so it can all completely drain, so the antifreeze may be the best option.

A slick system for antifreeze is to install a 3-way valve between the tank and pump, plus a tank drain valve. The 3rd port on the 3-way valve has a short tube that can be inserted into a gallon of RV antifreeze. Procedure: drain the tank, turn the 3 way valve, insert tube in jug, then run the pump and open each hot and cold water valve in the system until the water turns pink.

The hot water heater is especially prone to freezing. You can install a bypass around the water heater using three way valves. For freeze protection, bypass the water heater and drain the water heater. Then when the RV antifreeze in put in, it doesn't get into the hot water tank but can fill the hot water piping.

Manifold splitter
If there are just 2 cold water connections, a tee fitting should work fine. A brass fitting would probably require threaded adapters to Pex, which might end up using more space and having more leak potential than just using Pex tees.

Check valve
No check valve is needed at the inlet to the water heater. Just make sure the tubing connecting to the heater is rated for hot water. The cold water connection is at the bottom and hot water rises so no problemo. If you have a city water connection, then a check valve is required at the pump discharge to prevent city water from flowing backwards through the pump into the tank.

Pex fittings
I've never used Pex but I have used compression type fittings. The most important thing is to not have leaks. If that requires a tool it might be a good investment.

Other ideas
- The water filter could be connected on the hose on the outside of the van. This could save space and make changing the filter easier.
- Consider how the fresh water tank will be cleaned out. Even with a filter it can get skanky.
- Consider adding an outside shower! If I were investing in a hot water heater I know I would...
- Consider adding a city water inlet. If you have city water available, or camp at RV parks, it is much more convenient than filling and cleaning the tank. It would only add a check valve, tee, and inlet fitting.

freezing certainly an issue here. i am full timing in the van so the interior will always be maintained above freezing. winter here was mild granted but with insulation and small heat source the van stayed fine the entire season....my layout allows for the fresh and grey tanks to be installed inside. i do worry about some freezing at the point of entry though i may be obsessing a bit. i think im ok without antifreeze but your idea of a 3 way valve sounds like it might be put to other use??

im using a small 4 gall tank electric water heater and it has a standard pressure relief valve...i thought to run a hose from this to the grey tank in case it pukes?? sound reasonable?

sounds like i can just use a tee to split off the supply to the heater and keep it all pex...and youre right...space is at a premium so a simple tee is perfect.

i hadnt thought about cleaning the tank beyond bleach or other chemical. would i need to add more ports for fixtures specifically to do this??

i can definitely use the filter outside between hose and inlet and probably will at times for convenience. filtering the water before it enters the tank would keep it relatively clean to begin with no? i also figured the size of it was small enough that it would be drained and filled regularly. how often do these things need to be cleaned or sanitized if not being winterized?

i saw a combination city/gravity water fill box with locking door...seems like having the ability to do city water (even though i wont need it for that purpose specifically) as well as gravity is a good idea. good point about being at parks and such!! i would love to keep the inlet sort of stealthy and this box would be a challenge to do that unless i paint it. have to weight the pros/cons but im leaning towards having both.

no shower. i use wipes currently. lots of them. and i grab a shower at work or family when i can. adding hot water is going to be wonderful enough. really wish i could have afforded a top to stand or a extended body or a sprinter (lol). a shower would be great but im doing well without it. outside shower is doable if i where to be camping more. as it is, my parking space is very private but not enough to set up an outdoor shower...lol i can see the "man" putting an end to it with my luck

thank you very much for your input. very helpful because its frustrating to hit a bump when you thought you thought of everything

cygvan · 04-25-2012, 04:57 PM

Quote:

Originally Posted by witoke

I think a back flow preventer valve is probably a good idea just to forestall any problems with the heater cycling on to maintain water temperature and to be cautious in case water will sit in the heater for long periods between uses. But remember it will mean the heater will not drain automatically so unless you add a drain valve on the heater loop you'll have water sitting in there.

Pex tools are now really quite reasonable, last one I bought with the adaptors was about $40 at one of the big box stores. They are so quick and easy to use, it will save hours over conventional plumbing and the system is very reliable. It does have a fair amount of forgiveness to freezing as well since the tubing is flexible. I introduced it to a plumber friend of mine who thought that the tools were still very expensive. He won't use anything else now unless someone requests copper.

And just FYI, unless you need shower/irrigation level water pressure, the Shurflos are a bit of overkill. You can get a small in-tank pump like this:

<http://www.busdepot.com/details.jsp?partnumber=255070805>

that is more than adequate for a faucet flow and is a lot cheaper. The last one I had in my Westfalia lasted 28 years....

regarding the water heater....the plan is to turn it on to heat the water in the tank about 20 mins before i need it. then turn off power. so, that should take care of any excessive cycling...will water always being in the tank be an issue? to drain it in case i need to change the anode or other maintenance or failure, where should i locate a drain valve? on the hot water out side?

yeah pex is looking like the way to go...i read a little bit more and found out that there are a few ways to connect it all and i did see some reasonable tools...cant wait to dive in!

thanks for the recommend on that pump...i will check it out...funny, the pump is the one item that i didnt research multiple brands on...shurflos seem so ubiquitous...but it is better to look around...

thank you as well for the input...hope to show the results of the build soon...

cygvan · 04-25-2012, 05:09 PM

http://www.busdepot.com/details.jsp?par ... =255070805

pretty neat. and cheap!

do you know what the flow rate is and how it mounts inside the tank?

witoke · 04-25-2012, 10:38 PM

http://www.busdepot.com/details.jsp?par ... =255070805

pretty neat. and cheap!

do you know what the flow rate is and how it mounts inside the tank?
___________________

Y'know, although I did have to replace one once I just cannot remember how it was mounted. I think maybe the tubing and wiring held it in place down at the bottom of the tank. The flow rate is fine for a sink; filling pots and kettles, washing hands etc. It's actually a pretty good rate for a van since you don't use that much water when you turn on the tap. I have a Shurflo that I use for moving more serious quantities of water, like pumping bilges dry or transferring fresh water from one tank to another.