Water Temp Changes

[RVhiker]

When we boondock we want to conserve water. So we often turn the water flow off when using the shower. The idea is that you adjust the water temperature to comfortable once, then turn the valve on the handle off and turn the water back on when needed. That works well, except that when the water is turned back on again using the valve on the handle, the water temperature has changed from comfortable to way, way too hot. This has happened on my Jayco as well as another fifth wheel.

When both cold and hot water valves are on - and the valve on the handle is off - hot water can flow backwards into the cold water line, which means that when the valve on the handle is turned on you get a mix of hot water with hot water. The hot water seems to be under slightly higher pressure than the cold, so it can flow backwards into the cold line.

The solution for me was to install a check valve in the cold water line as close as possible to the shower head. It was fairly easy to do. The first picture below is "before" and the second is "after. The line sprayed with a bit of black paint is the cold line, the one needing the check valve that supplies the cold water shower valve. I had to modify the lines a bit to get the check valve as close as possible to the shower valve. Since my check valve is brass (and a bit heavy) I mounted the valve to the wall with a couple of 3/4" pipe support clamps.

[33 RLDS]

I might have to try that. Ours does the same thing. I learned to get out from under the water for the first few seconds as it gets pretty hot !!

[mcfarmall]

I'd try to find a slim in-line ball check valve that way positioning wouldn't be a concern. Looks like it works! Good job on the solution!!

[Seann45]

Mine goes the other way and is way too cold.. but seems like a good idea..

[3'senough]

Good mod. Just remember to run anitfreeze or air through it if you winterize as it will not back feed with the low points.

[troutslayer]

Very nice mod!

[RVhiker]

Thanks for the replies. It is really quite a relief to be able to use the shut off on the handle and not be blasted with hot water when turning that valve back on.

Seann45, seems like it would work with the cold water problem, too; I have read of this cold issue, but never found an explanation of what the cause is. But it sure seems like a check valve might be the cure.

I did find a sharkbite 1/2 inch check valve; it might be more a more convenient install for some.

[RedHorse1]

Happens in the 5th but I don't recall having the issue with the hybrid. My current solution is to let the shower "dribble" some rather than shutting it completely off.

[Curious by Nature]

I am permanently boondocking on a property I bought. A much simpler solution is to install a terrarium thermometer on the hot water tank with the display inside. Turn on the tank until the temperature is in the 97 to 105 F range, shut off tank. Go have your shower using the hot tap only. I keep a plastic dishpan in the tub to save the cold water from the lines for dishes. Saves your water and your propane!

[Jmooney]

Great idea. May have consider this one myself

[RVhiker]

I like re-purposing a device for RV use. As a terrarium remote thermometer, it costs about $10. As a special digital remote RV water tank temperature sensor, it would be $50. Great idea. Of course, heating the hot water to 97 to 105 does limit your supply somewhat.

[Curious by Nature]

Boondocking isn't for long, hot showers. Navy shower, 2 Gallons, tops. A little harder for DW, she has long hair!