Help - No hot water after un-winterizing

[richarus]

2020 Flying cloud - This new model has a single bypass valve. We just hit the road again. The by-pass valve on the water heater has two settings winterize and in use. I changed it to in use and and hooked to city water. Water pressure is normal for cold water but very low for hot water. Water heater on gas is burning normally. When I open a spigot for hot water, it is only warm for a few seconds then goes cold again. Has anyone else experienced this. Is a there a problem with the bypass valve? Wishing that this system had the old type of bypass system. Any advice is appreciated.

[BayouBiker]

This comes up a lot after dewinterizing. Most often is crud in the mixing valve and not much hot water is getting through. You should check the winter valve which really is the cold water inlet to the water heater to make sure it is fully open. You could release the heater pressure valve to verify there is good flow into the heater.
Careful not to get burned or wait for the water to cool off.

[BayouBiker]

So given that the tank has plenty of pressure and inflow, and given that you have low hot pressure at every faucet, the automatic mixing valve on the outlet of the water heater is suspect. It does have a tendency to get plugged with a combination of minerals and sludge from the antifreeze mixing and reacting with other gunk collecting in the pipes from use. Some people have good luck removing the valve and cleaning it out with soap scum cutting bathroom cleaner followed by a vinegar soak. Others end up having to replace it. It is a bear to remove.....

[DCPAS]

Originally Posted by richarus

2020 Flying cloud - This new model has a single bypass valve. We just hit the road again. The by-pass valve on the water heater has two settings winterize and in use. I changed it to in use and and hooked to city water. Water pressure is normal for cold water but very low for hot water. Water heater on gas is burning normally. When I open a spigot for hot water, it is only warm for a few seconds then goes cold again. Has anyone else experienced this. Is a there a problem with the bypass valve? Wishing that this system had the old type of bypass system. Any advice is appreciated.

Exactly the same thing happened to us. There is a screen before the mixing valve which I believe got blocked by whatever was in the tank from when I used compressed air to winterize. Over a few days it unblocked itself and started working again. I tried to remove the mixing valve but couldn't with the tools I had with me. When I got home I used a cleaning wand on the tank and am hoping that will take care of it, but I won't know until we use the trailer again. I am going to close the water input to the water heater next time I use compressed air.

[abqdor]

Like everyone has said, it is surely the mixing valve. Being such a new unit, I'd be surprised if it has accumulated a lot of gunk. When I took the mixing valve apart, there is a shut off spring inside that had become unseated probably from winterizing with compressed air. Here is a link to a previous thread with pictures of the mixing valve.

http://www.airforums.com/forums/show...errerid=103283

[PatLee]

This happened to me and the cause was my own impatience. Be sure to run the water awhile to fill up the 6-gallon hot water tank. Don't turn on your hot water heating switches (propane or electric) until you're sure the hot water tank is full. When you do flip the hot water heating switch, give it awhile to warm up the water.

[richarus]

Hi Brian,
Thanks for your advice. I am pretty sure that you are right about the mixing valve. I have located it but it definitely is not easy to remove. Any tips for removal? Do I just need brute force?

[BayouBiker]

Brute force and a good angle at it seems to be the ticket. I don't have any useful tips unfortunately.

[richarus]

I was able to stick the rubberized handle of my channel grip into the outlet of the valve and get enough leverage to loosen it. Cleaned it up including the check valve and screen which seemed to be somewhat clogged. It is now working albeit with lower than normal pressure. I think I will replace the part when we get somewhere that I can get a replacement. I appreciate your help as well as others in the group.

[Kingsford]

We had this issue same on both our 2017 and then our 2019 Flying Could, on the second trip it would usually resolve itself. I always suspected it was the mixing value based on research and symptoms. I took it in for warranty work and they said it was a bad circuit board. I am waiting to see if it happens again next month on our first trip of the season.

[Baby Zeppelin]

Originally Posted by abqdor

Like everyone has said, it is surely the mixing valve. Being such a new unit, I'd be surprised if it has accumulated a lot of gunk. When I took the mixing valve apart, there is a shut off spring inside that had become unseated probably from winterizing with compressed air. Here is a link to a previous thread with pictures of the mixing valve.

https://www.airforums.com/forums/show...errerid=103283

abqdor, your link did not work for me. Would you repost it please?


thanks!

[abqdor]

Sorry about that. I didn't try to open the thread before posting it. Here is the earlier thread with pictures of the mixing valve once I pulled it from the hot water heater. My post is #16 & 17.

https://www.airforums.com/forums/sho...errerid=103283

[Baby Zeppelin]

Originally Posted by abqdor

Sorry about that. I didn't try to open the thread before posting it. Here is the earlier thread with pictures of the mixing valve once I pulled it from the hot water heater. My post is #16 & 17.

https://www.airforums.com/forums/sho...errerid=103283

Thanks. Now I wonder if I should proactively clean my mixing valve before "unwinterizing" the trailer.....

[abqdor]

It's a pain to remove the mixing valve. I have gone two years without experiencing the problem again and I still winterize the way I always have with compressed air.

[richarus]

Originally Posted by abqdor

Sorry about that. I didn't try to open the thread before posting it. Here is the earlier thread with pictures of the mixing valve once I pulled it from the hot water heater. My post is #16 & 17.

https://www.airforums.com/forums/sho...errerid=103283

Looking at your pictures it looks like the same thing I saw when I removed my valve, i.e. the problem is likely with the check valve and screen that is attached to the valve. I am fortunate in that access to the valve is pretty easy in my rig. Maybe Airstream is getting smarter? I plan to buy an extra valve to keep on hand if it ever needs replacing.

[richarus]

Originally Posted by Baby Zeppelin

Thanks. Now I wonder if I should proactively clean my mixing valve before "unwinterizing" the trailer.....

In my opinion “if it ain’t broke, don’t fix it”. If you are able to readily access the valve, perhaps keeping a spare around just in case is the answer. Now that I have fixed it once, I think I can easily take care of it on the road if it happens again.
Rick

[Jwf]

Also check your outside fawcet is turned off as well. And did me it was still some air on the tank and lime that resolved itself after awhile.

[BillTex]

Originally Posted by PatLee

This happened to me and the cause was my own impatience. Be sure to run the water awhile to fill up the 6-gallon hot water tank. Don't turn on your hot water heating switches (propane or electric) until you're sure the hot water tank is full. When you do flip the hot water heating switch, give it awhile to warm up the water.

This.

[Baby Zeppelin]

So I went ahead and removed and inspected the mixing valve on my AS, figuring after three years of ownership it might be partly clogged.


To my surprise it and the check valve between it and the tank looked clean and shiny. Soaked them both in hot water and vinegar before reinstalling them as a precaution.

[BayouBiker]

Where do you get your water? Must be nice and soft!