RV Plumbing Problem

[CatTwentyTwo]

We ran into a little problem with our bath and kitchen water faucets last week that we have never seen before. When we open the cold water tap, it will run hot water for about 10 seconds or so before the water gets cold and then with the tap off, it doesn't take very long at all for the line to get heated again. I have no idea where to start looking and was hoping that someone here might have some ideas. The trailer was connected to city water if that makes any difference.

 

[Bob_VT]

Re: RV Plumbing Problem

You have a check valve that is failing....... probably at the water heater.

 

[gstanton]

Re: RV Plumbing Problem

Just a guess... the hot water is coming from the hose that is sitting in the sun? Once the hot water works it's way through, you're getting cooler water. I put the excess water hose well under the trailer - out of the sun - to help cool the initial water coming in.

Been RV'ing for about 30 years.

 

[CatTwentyTwo]

Re: RV Plumbing Problem

Thanks for the reply Bob, it makes sense that something is failing because we have had this trailer for 25 years and have not seen this before. I don't think we have check valves though, I just looked at the water heater and all I see are the hot and cold hoses hooked to short pipe nipples. Under the sinks all I see are T fittings in the lines. A check valve sounds like a good idea. I guess it would go in the cold water line at the heater so hot water wouldn't back up the line?

 

[CatTwentyTwo]

Re: RV Plumbing Problem

Just a guess... the hot water is coming from the hose that is sitting in the sun? Once the hot water works it's way through, you're getting cooler water. I put the excess water hose well under the trailer - out of the sun - to help cool the initial water coming in.

Been RV'ing for about 30 years.

I hadn't thought of that, but no the trailer and hose were in complete shade. This was definitely hot water from the water heater.

 

[NW Redneck]

Re: RV Plumbing Problem

The check valves are usually right at the inlet & outlet fittings of the HWT. They are usually brass or plastic. Another possibility is the HWT bypass valve is patrially open or is failing.

 

[CatTwentyTwo]

Re: RV Plumbing Problem

The check valves are usually right at the inlet & outlet fittings of the HWT. They are usually brass or plastic. Another possibility is the HWT bypass valve is patrially open or is failing.

I've opened all the doors and removed every drawer that I can to see the water lines and am 99% certain that there are no check valves or bypass valves anywhere. This is an old Wilderness trailer and maybe they just didn't install check valves back then. I have no idea why we wouldn't have seen this problem before, but I am going to install a check valve at the heater and see what happens. I promise to report back after I get the valve installed, thanks for all the suggestions.

 

[CatTwentyTwo]

Re: RV Plumbing Problem

I installed a check valve in the cold water line at the water heater and it seems to have fixed the problem. We have nice cold water now from the kitchen and bath cold water taps. Thanks to everyone for your suggestions.