I'm in Hot water !

[Inhotwater2023]

Water was operating normally, both hot and cold until today. Now I have hot water on both in hot and cold water lines!
No valves were switched unless by accident.

Has anyone seen this before?

Thank you


2015 Cameo 5th wheel CM38FL16

[dagst1]

Make sure your shower handles are closed. Sometimes if you turn off the shower head but not the handles it could mix hot and cold allowing hot water to the other faucets. Worth a shot.

[Tom Casper]

We have had this from new on a 2012 Patriot. Neither I, the original dealer nor subsequent shops can pinpoint it. I think it must be magic. If you let the "cold" side run hot for a few gallons worth it acts normal, but that involves wasting lots of water so we just live with it. Local shop that has looked at it previously wants me to bring it in over winter with no charge to look again, they are baffled. I may just pull it from winter storage here in Wisconsin and let them have a go again.

[Papa-T]

Also check the outside shower if you have one to make sure the hot and cold isn’t turned on and it’s shut off with the push button at the handle.

[Inhotwater2023]

There is no shutoff on the shower head so that isnt it. More hunting today to attempt to isolate it. Will advise if solution is found.

[Papa-T]

If you can’t figure it out. Mr. Google gave me this too. “Adding a check valve leading directly into the cold inlet at the rear of the water heater will indeed negate the migration of heated water out of the heater through the cold inlet. This process is exacerbated by a siphoning effect when you open the cold faucet to the sink.”

[Papa-T]

Also make sure you have the bypass valve behind the water heater in the correct position. https://youtu.be/uv_KbOPlATw

[Dallasrules]

Originally Posted by Inhotwater2023

Water was operating normally, both hot and cold until today. Now I have hot water on both in hot and cold water lines!
No valves were switched unless by accident.

Has anyone seen this before?

Thank you


2015 Cameo 5th wheel CM38FL16

I get hot water when I flush the toilet in my 1/2 bath. I believe that it is because the hot and cold water lines lay against each other near there and it heats the cold water line. Although, now that someone else mentioned it, it might be due to back flow from the hot water heater because it is very close to the toilet. About 1 foot away through a wall.

[Duke4857]

Check your hot water tank bypass valves. One of them may have started letting hot water into the cold water. Just a thought.

[Inhotwater2023]

The 5th wheel is parked in sw florida and the bypass valve for the water heater is located a significant distance from the water heater.

The solution was found by plumbing around the bypass valve. In doing so we eliminated that valve as a potential problem and were able to isolate a check valve in that branch that when removed, pretty much fell apart in our hand, it was allowing hot water to migrate to cold water side.

Thanks to each of you for offering ideas

[dagst1]

Thanks for reporting on the fix.

[Papa-T]

Glad you got it figured out.