One way valve on hot water in shower

[arcsum68]

Hi, I am not able to find what I am looking for and was hoping someone could point me to some literature or instructions on adding a one way valve to the hot water side of the shower valve. I watched a video awhile back where they mentioned they did this, but offered no details. Per the video when you use the switch on the showerhead to shut off flow, the cold water will back fill into the hot water side since the pressure is greater and thats why when you turn it back on it will be cold for a few seconds. By adding a one way valve to hot water side that cold water cannot get into the hot water side. Any recommendations on how to accomplish this?

[stormyboy]

Hey arcsum68,

It seems like you already found a solution. However, I recently wrote an article about this problem. Maybe it can still help you in a way.

This is the article I'm talking about:
https://www.linktonature.com/rv-water-blast-fix/

Hope this makes it clear to you 🙂

Storm

[arcsum68]

Got decently far today, before I realized that the valve itself was bad. Not deterred, just delayed, typical Chinese manufacturing. Pay less now and pray for the best. In my case, I needed a valve that was narrower than most because of my corner shower and there was not much to choose from. Having the bad one to plop in there I realize now could go bigger, but it would look odd so I will give this one another chance.

Is there a way to attach pics, or a recommendation for who can host? The service I used to use now requires a paid account.

[beemerphile1]

punomatic wrote:
I used one of these between the hot water pipe and the hot faucet, and then I added one of these at the base of the shower head hose. No more icy or scalding water when taking a Navy shower in the TT. Pretty easy install.

Exactly what I did, either I copied you or you copied me. Either way it works perfectly.

[mobeewan]

ktmrfs wrote:


another possible cause of the cold water problem is WH bypass systems with ONE lever, rather than the TWO lever systems. The one lever systems use a one way check valve that often has highly non linear characteristics. The result is very noticeable water temp changes with flow, very noticeable when water is down to a trickle then back up again. Solution, pull the check valve that is installed and install a WH bypass with two levers. That solved our issue along with two other camper friends complaining about the same problem.

This is exactly the issue. The water heater outlet check valve acts as a slight restricter to the flow of hot water. When the shower wand is shut off, it continues to trickle. Since the hot water flow is slightly restricted, it is over powered by the cold water flow. The hot water flow stops and cold water fills the shower hose. Cold water cannot back up into the hot water line, since the check valve at the water heater will not allow it to and hot water is not magically compressible by cold water. The cold water blast is from the cold water filling the 6 feet of shower hose as the water continues to trickle from the shower wand head.

There are three ways to solve the problem. Remove the check valve at the water heater outlet and use a 2 or 3 valve bypass, add a temperature controlled mixing valve to the shower lines or add a shutoff valve to the shower hose.

[NRALIFR]

Good call zurncompany. I’ll get right on that.

As soon as I find a big enough spot for it, that is. :R



:):)

[zurncompany]

Water pressure control valve ZW209 provides steady downstream pressure and allows high flow rates. Standard features ease maintenance and repair, delivering the lowest total cost of ownership.

***Link Removed***pressure reducing valve is an ideal choice when you need to open or close a valve electrically. It comes with Wye strainer and isolation valves to ease maintenance and the pressure gauges, wye strainer, isolation valves, and epoxy coating ensure lowest total cost of ownership.

[arcsum68]

Ordered THIS after discussing the options with the wife. We both like the valve idea, though I do believe the one way valve and an actual shutoff valve would have worked. The shutoff is the secret, otherwise the cold water will just fill up the hose, especially if the cutoff is right at the faucet instead of the end of the hose.

[arcsum68]

Hmmm, looks like this guy did it without having access to the rear. This sounds SUPER appealing. I am going to investigate, but I really like this idea.

https://wackypup.blogspot.com/2019/09/best-low-cost-luxury-mod-upscale-rv.html

[arcsum68]

NRALIFR wrote:
I tried most of the “All you have to do is just.........” suggestions given here, with very little improvement. I say “most” because when you dry camp as often as we do, and only have a 30 gallon fresh water tank, dribbling the water works against our need to stretch every resource needed to extend our stay.

What finally fixed it for me was a Thermostatic Shower Mixer Valve.

:):)

I mostly dry camp as well, and my trailer only has 40 gallons fresh water. It's really the one negative thing I have to say about the trailer so far, very small amounts of fresh and gray water storage. Even 50 gallons each would have been very much appreciated.

I love this idea, but I think I will be pretty limited since I have no access from the outside. The only place I can do anything from, is the inside of the shower at the valves or maybe inline. There is an access panel for the water heater/heater, but I havent opened it up yet.

In the video I watched the guy had a room behind the shower and cut into the wall so the check valve was right at the controls.

[NRALIFR]

I tried most of the “All you have to do is just.........” suggestions given here, with very little improvement. I say “most” because when you dry camp as often as we do, and only have a 30 gallon fresh water tank, dribbling the water works against our need to stretch every resource needed to extend our stay.

What finally fixed it for me was a Thermostatic Shower Mixer Valve.

:):)

[arcsum68]

opnspaces wrote:


Are you having a problem with the cold water blast in the shower or does the one way valve just seem like a good idea.

Many RV water heaters already have a check valve at the exit line, it's possible yours already has this.

Does your RV shower head should continue to dribble water out of it even when you flip the switch off..

Thanks all for answering.

I get a cold blast every time, so it seemed like a good idea. If mine had such a valve, would this not be an issue or is what I have about as good as it gets? Pretty minor complaint, just trying to make things nicer.

I have an Oxygenics shower head and it does indeed dribble when turned "off".

[ktmrfs]

wa8yxm wrote:

arcsum68 wrote:
Per the video when you use the switch on the showerhead to shut off flow, the cold water will back fill into the hot water side since the pressure is greater and thats why when you turn it back on it will be cold for a few seconds.

Since both the hot and cold water are pressurized by the self same PUMP that.. it male bovine produced organic fertilizer (AKA BS)

What happens is when the water stops the hot cools a bit and "Contracts" sucking cold in. The solution is to use a better valve that does not 100% turn off flow. the Oxygenics "Smart Pulse" valve is like this. it allows a dribble of watter to flow. So does the generic valve I got at Mennards years back (Alas no link it's been 15 years)

Either of these solves the issue for about 10 bucks.

another possible cause of the cold water problem is WH bypass systems with ONE lever, rather than the TWO lever systems. The one lever systems use a one way check valve that often has highly non linear characteristics. The result is very noticeable water temp changes with flow, very noticeable when water is down to a trickle then back up again. Solution, pull the check valve that is installed and install a WH bypass with two levers. That solved our issue along with two other camper friends complaining about the same problem.

[wa8yxm]

arcsum68 wrote:
Per the video when you use the switch on the showerhead to shut off flow, the cold water will back fill into the hot water side since the pressure is greater and thats why when you turn it back on it will be cold for a few seconds.

Since both the hot and cold water are pressurized by the self same PUMP that.. it male bovine produced organic fertilizer (AKA BS)

What happens is when the water stops the hot cools a bit and "Contracts" sucking cold in. The solution is to use a better valve that does not 100% turn off flow. the Oxygenics "Smart Pulse" valve is like this. it allows a dribble of watter to flow. So does the generic valve I got at Mennards years back (Alas no link it's been 15 years)

Either of these solves the issue for about 10 bucks.

[punomatic]

I used one of these between the hot water pipe and the hot faucet, and then I added one of these at the base of the shower head hose. No more icy or scalding water when taking a Navy shower in the TT. Pretty easy install.

[Dusty_R]

What I've done to fix that problem is to put a garden hose/GH valve at the shower head. I get from Tractor Supply water pipe to GH adaptors.

Dusty