No Hot Water 2019 Vista LX 35F

[John Vista]

Just getting our Winn Vista LX dewinterized and ready for use….filled fresh water tank, turned on pump, and eventually the cold water started running at all faucets. No water coming out of hot water side. Turn on any hot faucet - no water……and pump doesn’t even come on. Checked pressure relief valve on water heater, and when I tripped it, water came gushing out, so apparently the hot tank is filled.

I don’t recall this ever being an issue in past 3 years that I dewinterized it.

Wondering if there is a valve on hot water side that maybe got closed by mistake, or possibly an airlock?

Any insights suggestions would be very welcomed. Thanks all. J.

[Morich]

It looks like you have a pretty open/shut case of stuck or clogged check valve at the point where hot should come out to the kitchen faucet close by!
Click this snip to see what I think is the problem.

Cool water comes in to and past the bypass valve. If that valve is set wrong, you get no water in the tank. You've done a good job of answering that question!
That bypass set correctly lets the water go in the heater on the bottom and come out the top. There is a check valve at the point where it comes out of the back of the heater!
With the next point being the kitchen faucet and so near, I'm saying pretty sure a stopped up check valve. Not very far to the kitchen if I see it right!
Bummer ! But not terribly confusing on this one!

I'm assuming no water flow when the hot side is opened on any faucet, correct?

[Ray,IN]

Winnebago seems to like installing a check valve on both cold inlet and hot outlet of water heaters. If the winterizing bypass valves are all in the correct position for normal use, it must be a the hot outlet check valve.

[John Vista]

Good info so far…..stuck check valve makes sense. Is there any advice for fixing? How do I get at this - certainly not from the small exterior access panel.

To answer the one question…the hot water tank seems to have water in it, .. and there is presently no flow from any of the hot water faucets in the RV.

[Ray,IN]

How to access the plumbing to replace the check valve is always a big ?, for each individual RV.

[Morich]

Reason for me to feel so certain it is the check valve on the output? I normally don't step out on that limb very far!
But when we look at the water heater in this RV, there is one way in and only two ways to get out!
When you can open the temp and pressure relief valve, we can say for sure that water is getting in! Also we can say water is getting out at that valve!
The bypass valve seems to be correct because water is getting in!
There is always "some" chance the straight line to the first faucet "might" be clogged so we have a choice of thinking a check valve is clogged/stuck, which is a semi-common problem OR we have to say the line is plugged in the middle of the run and that is not one I've ever seen!
But the bad side of that is a real bummer in many cases because there may be two choices and both tend to be ugly!

If you are lucky, there might be a chance you can spot a cabinet. etc. behind the heater where you can pull a few plywood panels off for access.
But when I look at the odds, I have to think there is a good chance you have to pull the heater out!
Not good and I hope you are able to spot a better way? You likely have access to the bypass valve near the rear of the heater? Any chance of enough room to remove the check valve, even if it required cutting the pipe and then repair it?

That's where the best of drawings will often leave us guessing as it can show us where but not HOW?

[John Vista]

Thanks for the input. Morich….do you have a web link to the water heater diagram you posted - or is this a cut from the manual?

[Morich]

My "goto" for lots of things is the parts catalog!
It's an interactive set of drawings. We can choose the RV, even down to the build date, etc., get the correct RV, then choose which parts we want to see. Water, electrical drains, etc.
https://catalog3d.winnebagoind.com/menu/Parts.htm
It takes a bit of learning curve to drive well but I love it as a way to see things without having to leave my chair or take anything apart!
Find it on the parts list at right if you know the name but not where and it lights in yellow on the drawing.
If you see an item on the drawing but don't know the name, click it on the drawing and it pops up on the list with a part number!
Hint? To keep an area of RV centered, go to lower left to the +, click it, then click a part on the RV to keep centered! Do this before zooming!

I love it but then I also admit I spend way too much time just waiting for swapping info on business questions. Swapping info on RV is the "entertainment " in between getting paid to do it on bigger stuff!