Cold water when shower turned back on

[wallet14]

Hi all:

we bought our travel trailer almost a year ago now and we have had issues when we use the shutoff in the wand of the shower and lather up and turn the water back on that all the water coming out is cold. I have read elsewhere that what happens is the pressure is higher in the cold side so that back feeds into the hot water. My understanding is that I need a "one way valve" but I am not sure exactly how to do this. I would like to do it this winter to ensure dw and the kids have great showers this year and are happy. We have a 2013 Springdale 282. I took a picture of the plumbing behind the showers wall in the bunk area where i guess i would need to put the valve. Please provide any assistance you are able to.

Thanks,
Josh

[Andymon]

Ours does the same thing but we just don't use the shut off valve. I take ahot shower as does my GF and we never run out of hot water. We usually wait about 30 minutes between showers.

[JRTJH]

The hot water heater winterization kit is the culprit. It is composed of one twist valve on the cold water supply and a one way valve (with no control) installed in the hot water outlet of the HWH. When you turn on the shower, faucet, water flows from both the hot and cold sides of the faucet. When you close the shower diverter, cold water flows past the hot water one way valve and into the hot water supply line. When you open the shower diverter valve, the cold water flows from both the hot side and the cold side of the shower faucet giving you a "surprise".

In the older winterization kits, there were three valves, one on the HWH inlet, one on the HWH outlet and one between the two. The only way I know of to eliminate the cold splash syndrome is to install additional manual valves in the HWH winterization plumbing. Then you can prevent the cold water from flowing past (around) the HWH one way valve.

There are several threads on the forum about this topic, use the search feature to find them. Lots of good information on how to modify the existing winterization kit is posted in those threads.

[Sherwood]

Good thread. I have the same problem when taking a shower and when I shut the water off at the shower head, cold water then spurts out and is rather unpleasant when lathering up. It didn't do it in my old trailer and I do recall that one had another shut off valve on the bypass. Guess its time to search for that mod.

[wallet14]

Thanks for the info! Wouldn't it also be beneficial to put a one - way valve right at the back of the shower to prevent any back flow to the hot at that location? I searched the forum before but i haven't found much. I will certainly look into correcting the bypass for the hwh.

[JRTJH]

One solution is to add one way valves on the shower faucet. The cold/hot water supply lines originate at the hot water (theoretically) and adding valves anywhere along those lines will restrict the flow of cold water into the hot water side. I think you're better off to correct the problem at the source (hot water tank winterization kit) and be done with it.

Here are a couple of threads to get you started:

http://www.keystonerv.org/forums/sho...ht=cold+shower

http://www.keystonerv.org/forums/sho...ht=cold+shower

http://www.keystonerv.org/forums/sho...ht=cold+shower

http://www.keystonerv.org/forums/sho...ht=cold+shower


And, Here's one solution to the problem in detail:

http://www.modmyrv.com/2009/04/12/rv...y-check-valves

Here is the solution I'd recommend. It completely isolates the hot and cold water supplies and prevents cold water from entering the hot side. This is the way all bypass systems were installed until the advent of "saving money" came along and two manual valves were eliminated by installing a one way valve. Only problem is that it really didn't save money since we all tend to reinvent the old system as depicted in the adjoining picture.

[f6bits]

My water heater has a single valve at the lower T. I've not experimented with it, but I'd think it should be blocking the route the cold water takes. I still get the cold water blast even when I shut off the Hot and Cold in the tub to save water.

The ModMyRV link looks to only solve the problem with using the shower head valve. I seem to have a different problem, considering I use the H and C knobs to shut off.

For those who try the ModMyRV approach, Amazon has nice check valves for about $16 each:
http://www.amazon.com/dp/B00506ET10

[wallet14]

Thanks john!

F6bits - check out http://www.amazon.com/gp/aw/d/B000KE...110_SY165_QL70 for the shutoff around the hotwater heater. Maybe that will help you. I am considering doing both as a little overkill can't hurt