Hot water in cold water circuit

JoeB · 08-03-2019, 11:00 AM

My 2008 Itasca Sunova has developed an issue where I am seeing hot water coming from the cold water side of the plumbing. Additionally I am finding small white particles in the aerators and it is plugging up the water supply valve to the toilet.I do not know if these two issues are related. This problem is most prevalent when connected to a pressurized domestic water source as opposed to operation from the onboard water source and pump.

I suspect that the foreign matter is coming from the HWT. I have drained it multiple times and have gotten modest amounts of this material when doing so. I have drained the fresh water tank and gotten NONE but I have found some in the INTAKE strainer to the water pump.

In an effort to troubleshoot these issues I removed the HWT outflow aftermarket check valve and replaced it with a simple three way valve in order to enable the winterization bypass when desired. I have not yet checked the intake check valve but because of the plumbing on the hot circuit side, common sense tends to say that the inlet pressure on the HWT SHOULD be higher than the outlet pressure therefore there should not be backflow out of the HWT. I need to check that check valve as I realize sometimes common sense doesn't count.

One last symptom; when i last removed the toilet to clear the blockage in the water valve, the whole time it was removed, about 15 - 20 minutes, I continued to get a trickle of hot water from the plumbing connection and from the open low point drain. I seemed like this was being siphoned from somewhere in the system like the HWT maybe.

Looking for any and all ideas from all of you experienced techy type people who may have experienced this before or who just know more that me.

Thanks in advance
JoeB

Morich · 08-03-2019, 12:08 PM

Some sorting of the problem is always good to start, so we might ask more about the white stuff. White stuff running through the lines is quite likely to foul the check valve and make them fail, half open, half closed and that as a result may cause the other problems.
So WHAT is the white stuff and where is it likely to come from? Are you familiar with the white hard water deposits from things like calcium? Think of what's left in tea kettles.
If not, one way to test is to add some of the flakes to some light acid like vinegar and watch for fizzing as the deposits are alkaline.
Or is it the lining of the hot water tank beginning to peel off and float around. Glass lined water heaters are not actually glass inside but fiberglass lined and it can peel off.
I would first want to find what and then look at clearing where it is fouling things.
It's all just a mystery and mystery stories are as good entertainment as I can find when it's too hot to breathe outside!

JoeB · 08-03-2019, 03:04 PM

Goog suggestion with the vinegar test. I have collected a sample of the material for chemical analyis. I used a small portion to do the vinegar test. I am not seeing any overt fizzing around the particles. Theses pieces feel hard but when I push on them with my fingernail they break and turn powdery. They could be the tank lining but i think further analysis will be required to rule that out.
In either case it seems most likely that the source of the material is the HWT. Assuming that is correct what force would cause the material to get into the cold water lines and then back on the intake side of the pump?
jcb

Morich · 08-03-2019, 03:34 PM

Not looked at the exact route and water flows in funny ways at times so , The source of it getting from hot to cold may be the major question and that is pretty easy to see happening. A check valve lets water flow into the HWT but should stop it coming out, but if a bit of the hard material gets stuck around the spring or opening of the check valve and doesn't let it close, water can flow both ways and then it gets into all kinds of currents and directions to move stuff back and forth depending on how fast and how long water goes in different directions as we use hot or cold and at different faucets. So I might guess it kind of wanders around all over the system?
Hate to say it but I'm guessing the water heater is shot.
Some ideas of how it could happen besides just wear is if the water heater was bypassed and empty when it was fired up as that might make it get too hot for the lining. Just a guessimate , there. I could see it getting a hole and then gradually bits breaking off. Never actually cut an RV heater open to see what the liner looked like, though.

rgvtexan · 08-12-2019, 02:19 PM

Check the valves for the outdoor shower. Sometimes the get left open, if the shower is shut off with the hose valve.

They sell a flushing wand for the tank.

https://search.yahoo.com/search;_ylt...e=E211US558G10

jerichorick · 08-18-2019, 08:26 PM

Quote:

Originally Posted by JoeB

My 2008 Itasca Sunova has developed an issue where I am seeing hot water coming from the cold water side of the plumbing. Additionally I am finding small white particles in the aerators and it is plugging up the water supply valve to the toilet.I do not know if these two issues are related. This problem is most prevalent when connected to a pressurized domestic water source as opposed to operation from the onboard water source and pump.

I suspect that the foreign matter is coming from the HWT. I have drained it multiple times and have gotten modest amounts of this material when doing so. I have drained the fresh water tank and gotten NONE but I have found some in the INTAKE strainer to the water pump.

In an effort to troubleshoot these issues I removed the HWT outflow aftermarket check valve and replaced it with a simple three way valve in order to enable the winterization bypass when desired. I have not yet checked the intake check valve but because of the plumbing on the hot circuit side, common sense tends to say that the inlet pressure on the HWT SHOULD be higher than the outlet pressure therefore there should not be backflow out of the HWT. I need to check that check valve as I realize sometimes common sense doesn't count.

One last symptom; when i last removed the toilet to clear the blockage in the water valve, the whole time it was removed, about 15 - 20 minutes, I continued to get a trickle of hot water from the plumbing connection and from the open low point drain. I seemed like this was being siphoned from somewhere in the system like the HWT maybe.

Looking for any and all ideas from all of you experienced techy type people who may have experienced this before or who just know more that me.

Thanks in advance
JoeB

Joe, you don't reflect which model you have. I picked this one from the list on the resources menu at the Winne website: http://www.winnebagoind.com/diagram/...d26p_plumb.pdf
I think you have a winterizing valve/bridge connecting the hot and the cold. This valve could be defective or partially operated. The more likely problem is that one of the check valves on the back of the water heater has failed and is not checking the flow of hot water back into the cold water side of the system.
I hope this information helps you solve your problem.

Happy trails,

Rick Y

Diesel-Lover · 08-18-2019, 08:43 PM

Perhaps its the winterization or bypass valves that are giving you a headache.

09 harley · 08-18-2019, 10:52 PM

Quote:

Originally Posted by jerichorick

Joe, you don't reflect which model you have. I picked this one from the list on the resources menu at the Winne website: http://www.winnebagoind.com/diagram/...d26p_plumb.pdf
I think you have a winterizing valve/bridge connecting the hot and the cold. This valve could be defective or partially operated. The more likely problem is that one of the check valves on the back of the water heater has failed and is not checking the flow of hot water back into the cold water side of the system.
I hope this information helps you solve your problem.

Happy trails,

Rick Y

Read this post again. This person has nailed it.