2004 Suncruiser: LP water heater runs, no hot water

[Tallman54]

Hello:

This is my first post, so please be kind :-)!

The 10 gal Atwood LP/Elec water heater in my 2004 Suncruiser starts fine on LP, but after 30 mins of running continuously, there is no hot water from any faucet. Today I replaced the ignitor, the thermostat and the ECO, thinking the thermostat was the culprit. Unfortunately no change. I am also experiencing pulsing of the water pump, except when I turn on more than one faucet simultaneously. My fresh water tank (80 gals) is at least half full.

I believe the hot water heater bypass valve is in the correct position.

I have run out of ideas and assume I am doing something wrong. A couple of days ago, I would receive hot water but for only a few seconds. Today I don't even receive any hot water.

I winterized using compressed air (pressure controlled), and upon refilling the fresh tank for the first time and running each faucet there are no leaks.

All suggestions welcome and appreciated.

Thank you!

[Morich]

I might ask a few questions to sort what might be happening as there currently seems to be two possible.
One needs to sort if the heater is not heating water correctly or if the water is not moving into and out of the heater tank.
One way to sort that question would be to connect to AC power and try the electrical heat to see if you then get hot water or not.

But if power is not handy, can you tell us more about what you are hearing when the heater is running on LP.

One should hear the heater light a few bit after you turn it on and then the main burner should stay on for some time to heat the six gallons to the right temp. So do you hear it light and then it burns for a while? If not one needs to check why it is failing.

As a second possible item, the valves which route the water past the heater may not all be in the correct positions. When you open the access on the outside, you should see a temperature and pressure relief valve which is the safety to stop pressure from going too high. You may first notice it as a fitting that has an open end and a lever which we can pull up to open the valve.

When connected to a faucet with the hose or when the pump is running and pumps up pressure, there should be water come out of this valve, if we carefully open it just a bit. Danger here if you have the heater on as it may be HOT, so avoid getting scalded!! If you have water fly out when cracking this valve open, the bypass valve letting water into the tank is right, so you may then need to check for a second valve to let the water out of the heater into the pipes! If you get hot water, it does tell you the heater is working but if only cold water comes out, more checking might be needed to see why.

Pulsing of the pump is often true and an adjustment on the pump is available to change it but it is somewhat a compromise and not unusual for it to cycle on as we open a faucet, build to the correct pressure and cut off only to cycle on again as we again lower the pressure in the pipes. It depends on how much water is running, how often it cycles, so no way to set it to cover for different water use at different times.

Posting more complete info on which RV you have including size or model number will let us get into more exact answers.

[Bones2003]

Tallman54, welcome to the forum. There is lots of good information here and people willing to help. The more clear information that you can provide will really help people answer your questions.

Regarding your hot water heater, here a few comments/questions: You say the LP burner comes on but after about 30 minutes there is no hot water.
1) When you say you do not get hot water does that mean that you get water out of the hot water faucet but the water is not hot or does it mean you get no water out at all?
2) Does the flame burn constantly for that whole 30 minutes?
3) Does any water drip out of the pressure relief valve on the hot water heater?
4) Are you sure there is water in your hot water heater? You can check by removing the drain plug but be careful if there is actually hot water in the tank so you don't get scalded.
5) If the LP flame comes on that whole time, how did you decide to replace all those components?
6) Many times Winnebago installs check valves on the water outlet and maybe the cold water inlet to the hot water heater. These check valves are notorious for failing in the stuck closed position. Can you tell if you have check valves on the back of your water heater?

If the burner is heating the tank then the likely suspects are the water heater bypass valve or the check valves. I am sure others will add more valuable information than I have given you. You can also search the forums for water heater problems because there are lots of posts with similar problems.

Good luck!

[Bones2003]

It looks like Morich and I were typing our responses at the same time! Morich is always a great source of valuable information and has helped countless people on these forums.

One word of caution however, it is best not to try to use the electrical heat unless you are positive that there is water in the hot water heater. Without water in it you could burn out the electrical heating element and just create more problems for yourself. It sounds like you might have water in your tank though so Morich's suggestion is probably valid.

[Tallman54]

Thanks to everyone who replied!

Hopefully I will answer all of the questions:

1. Burner ignites within a minute or so after turning LP water heater on

2. This evening after putting the new parts in, I allowed the unit to run for 30 consecutive minutes, thinking eventually the thermostat set point would be met and the burner would turn off (is this how it is supposed to work?).

3. The burner ran the entire 30 minutes.

4. Water does flow out of both the hot and cold sides

5. The water from the "hot" side is the same temp as from the "cold" side of each faucet, incl the outside shower

6. I replaced the parts as (a) inexpensive, (b) easy to access, and (c) when the burner ran the other day for more than 20 minutes without producing hot water, I thought perhaps the thermostat was defective as it appears to be the original.

7. When I filled the fresh tank last week, per the instructions in the owners manual, I opened the all of the hot water valves and allowed water to flow (connected to city water) for more than several minutes.

8. I have not tried the pressure relief valve or the drain valve, so will open the water heater drain valve in the morning to verify the heater has water (wouldn't it shut off after running for 30 mins if there was no water present?)

9. As for check valves, this is the first I have learned of their possible existence. I can barely see the back of the water heater so I don't know if my RV has these valves? When I winterized last fall, water definitely drained from the heater tank when I removed the drain plug.

Since I can't see your responses while typing this reply (perhaps I am using this system incorrectly) I hope I have answered all of your questions.

I will provide an update tomorrow morning as it is late here and well past the onset of darkness.

Thanks to each of you for your prompt and thoughtful responses, I truly appreciate your help!

[Tallman54]

My RV is: Itasca 2004 Suncruiser 35U. The water heater appears to be the original unit, and it is a 10 gal unit (model: GCH10A-4E).

[Tallman54]

Thanks for the caution re: electric mode. I have only utilized LP as I concluded if this doesn't work with the burner running as expected, I don't want to risk burning up the heating element by running in electric mode.

[Bones2003]

Tallman54, here are two links to your plumbing diagrams on the Winnebago website. Perhaps this will be helpful.

https://www.winnebago.com/Files/File...g35u_plumb.pdf

https://www.winnebago.com/Files/File...g_callouts.pdf

[Morich]

Originally Posted by Tallman54

Thanks for the caution re: electric mode. I have only utilized LP as I concluded if this doesn't work with the burner running as expected, I don't want to risk burning up the heating element by running in electric mode.

Good thinking and glad to see folks do correct what we each might miss! One thing I always try to keep in mind is that we are ALL prone to failure and that certainly includes me!

So the reason we like to get the exact info on which RV is that there is a ton of info online we can point to as it often leads to spotting the problems.

Parts catalog for your RV is here:
https://www.winnebago.com/Files/File...04/4ifg35u.pdf

Running down to page 270-271 gets a drawing of item nineteen which is
listed as "cover, valve, bybass, bright white" so it shows where to find that!
Easy way to point to where it might be expected on an RV that is still very much OEM!

More great info on plumbing here:
https://www.winnebago.com/Files/File...m/Plumbing.htm

Now you can go stomp a few of those little things that bug us?

[tderonne]

Originally Posted by Tallman54

Thanks to everyone who replied!
9. As for check valves, this is the first I have learned of their possible existence. I can barely see the back of the water heater so I don't know if my RV has these valves? When I winterized last fall, water definitely drained from the heater tank when I removed the drain plug.

If no water is flowing from any faucet on the hot side. Its the check valve. Very common problem. Kind of surprising it's lasted this long, unless the replacement has now failed.

One thread with some info. Lots more out there.

[Tallman54]

UPDATE:

The following is based upon my findings today. The water heater has been off all night.

1. When I opened the pressure relief valve, water came out, thus I concluded the tank was full (or nearly full).

2. I confirm the presence of a check valve in the cold line into the heater tank, and another screwed into the hot water out port near the top of the tank.

3. I concluded the cold water check valve must be OK given my tank appeared to be full, so I focused on the hot water check valve (fun to access...).

4. I drained the heater tank to minimize the water which might come out when I removed the hot water check valve. There was a lot of water in the tank, thus reconfirming my suspicion it was full (or nearly so).

5. When i removed the plastic hose fitting on the output side of the hot water check valve, a very small volume of water trickled out.

6. I removed the check valve and found it could be operated by my finger, but I do not have the correct female hose fitting size to allow me to test it outside of my RV, so I took photos, but just realized I apparently must upload them to Dropbox or somewhere else which provides a URL as this forum doesn't appear to allow me to upload direct from my laptop.


The lack of hot water anywhere in the RV makes sense now if this valve is defective, but the fact I can operate the valve with my finger, puzzles me (just a slight amount of pressure is all that is required to depress the piston within the valve). I expected to find a jammed valve, so I graciously seek your feedback, please, based upon this new info.

Thanks for all of the inputs (fyi, I am aware of the archived drawings, docs, etc, but thanks for sharing the links nonetheless!).

Best regards.

[Tallman54]

Hi, Tim:

Thank you. My RV has less than 14K miles on it as previous owners rarely used it due to health issues. This said, I do have water flow (albeit less than with city water connected) out of each hot faucet, but the water is the same temp as from the cold faucets. If the hot side check valve is bad, I understand you to say there should be no water flow from my hot faucets, which makes sense.

Earlier today I looked carefully at the plumbing related to my water heater bypass circuit and unless the valve is mismarked, it seems to be in the correct orientation. I guess a good test would be to take the drain plug out, leave the water heater off, turn on the pump then switch the bypass valve and look for water flowing out of the heater drain. Unless I am completely confused (entirely possible) this seems like a clear way to determine the correct orientation of the bypass valve. Do you agree?

Thank you!

[Morich]

A couple small points that may help.
One is on picture posting as it can be simple. When posting, hit "go advanced" to get a different screen and then try using the paperclip at the top and it brings up a different setup to let you pick photos on your machine. Be sure not to miss the final step of "upload" then you also have a preview, where I find it always important to check myself!

Some check valves are pretty weak and we can test them by simply trying to blow through each direction, one side should be total stop while the other may let you blow through, assuming a semi-weak valve?

Just as a test of myself and knowing I misread what I see at times? Maybe try the bypass valve turned different to see if it gets different action! There could always be some chance of the handle on the valve, broken loose and not actually turning the inside part which opens /closes the water flow? Kind of weird thought on that!
Is this the type valve you find for bypass?
I think of this as the handle pointing to the direction it lets water flow. Sound right to you?

[Tallman54]

Hi, Richard:

Thank you for the additional information. I am able to blow a slight amount of air through the check valve, in either direction, so am i correct to assume this valve needs to be replaced? I took it apart and verified the internal components seem to be robust, but without much effort I can blow air through it using my mouth.

I have attached a photo of the water heater bypass valve and its related plumbing, and also a photo of the input side of the hot water check valve.

I was not able to spend any additional time this pm troubleshooting so will make another attempt tomorrow morning. I use air to winterize not anti-freeze, so I think I will simply remove the internal parts of the check valve, reinstall it, then verify the water heater bypass valve is functioning correctly. At least this way I am able to eliminate a couple of possible sources of my lack of hot water from the faucets.

I do appreciate your help very much, thank you!

[Morich]

Well that does clear some questions, as that is labeled and about as clear which direction to turn as I have ever seen. What I have doesn't have any notes at all and it was a bit of guess on which of two knobs to turn which way but I think we can say you are NOT confused on the bypass part!!!
The check valve may not be a problem either as they will be more likely to leak through than to be totally stopped if you can blow through it. How much a small leak through would change things but there are some who have just simply drilled the check valve out when they found them stuck shut.
I've forgotten what their first problem was but maybe they will note this post and jump in with what they found changed when they drilled it out. It sounded kind of radical to me as I've not done that but if it worked, fine.

But that is where we get into the fact that the check valve is designed to keep the water from running back into the tank and should not keep it from going on to the faucet as long as it is not stuck shut! We don't get very much pressure when we blow through things so the city water is likely to be way more (40-50PSI?) than we can blow and even the pump is higher than lung power, so the water should have no trouble getting past the check valve. Hard water deposits and rust are the two things I think of as making check valves go bad but that one doesn't look too bad at all. Maybe a little soaking in vinegar as a way to clear that film off but nothing I would worry about.

About all I've got is that if the water is going in and the fire is burning, it should come out hot!

Another small point on picture posting is that the camera puts info on which way is up and the only way to get them to post right is to take the picture with the camera laying the other way! No big thing and most of us can see the big points most of the time.

[Morich]

Upon further thought????
Did you find one or two check valves?
Looking at this drawing and seeing two places where there are markings to show "V6" at two points, makes me wonder if that V6 is a check valve, one where you can spot it but a second under a cover at top where it might be missed and stopped up???


What has me wondering is that note on parts that I mentioned on a post earlier that says, "cover, valve, bybass, bright white". Did you get a look at the back side well enough to see any white cover that might have some bypass item hiding under it---or maybe a second check valve, etc.

I'm not understanding why they refer to the cover and use bypass as any description??? No access point inside for some second valve to open?

Terrible to think of a valve we want to use in a spot like that but there are times!!

[Tallman54]

Hi, Richard:

First of all, thank you again for your inputs.

I discovered two check valves, one on the cold water input line to the hot water heater (located on the lower backside portion of the water heater), and a second valve which is screwed into the hot water output port near the top of the backside of the water heater.

So I have a couple of new updates based upon my efforts today:

1. The hot water output check valve: I pulled it apart again and looked inside the brass portion with a flashlight. I immediately noticed a significant amount of black residue, especially in the area of the valve seating portion of the valve body. I took your advice re: soaking in vinegar, followed by some aggressive cleaning using multiple Q-tips (all of which quickly turned black). I reassembled the valve, and lo and behold, it now only allows air to pass through from the input side! Progress! So I chose to leave the spring, etc inside and install my "new" check valve back onto the hot water port of the water heater.

2. I ran my experiment in which I removed the drain plug from the hot water heater then enabled the water pump and changed positions of the "Normal" and "Hot Water Bypass" valve (located within a few inches of the water pump). Much to my surprise and chagrin, it quickly became apparent the valve is incorrectly labeled, and the correct positions are exactly the opposite that shown in the photo I posted last night... amazing and ridiculous this can still be a problem on a 17 year old motorhome!! It is now correctly labeled!

So my next step was to ensure there were no leaks related to removing and reinstalling the hot water check valve. Unfortunately this proved to be yet another adventure as I quickly found significant leaking at the backside of the plastic fitting which was attached to the output side of the hot water heater check valve. I had carefully wrapped the male NPT threads on both ends of the check valve with Teflon tape before reinstalling.

I chose not to deal with the Teflon tape again, so after procuring some PTFE white paste, I reinstalled the check valve again. Unfortunately the leaking was even more pronounced. I inspected the plastic nut (no cracks), and then decided to remove the check valve again and gut it as I thought perhaps it was causing too much back pressure within the plastic fitting (wrong-headed thinking but my patience was wearing thin at this point).

When I removed the check valve I realized the plastic "ring" in the enclosed picture was missing from the output end of the check valve (as shown in the second photo). When I disassembled and cleaned the valve, I had no idea as to the purpose of this "ring"... suddenly its purpose became very clear!

I reinstalled the check valve, this time being careful to ensure the plastic ring remained in place, snugged the plastic fitting, and thankfully the leaking had been stopped!

Eventually I was able to refill my fresh water tank, start the gas burner on the water heater (works better with the LP tank valve is open!), and miracle of miracles, with the "Normal/Bypass" valve in the correct position, hot water is now everywhere it is supposed to be within my RV!!!

It is sad to now realize, had I not simply accepted the labeling on the "Normal/Bypass" valve and verified the correct position at the very beginning, I could have saved myself over 12 hours of effort and a few bucks on parts, etc.

One last comment: without the help of various folks on this website, I would likely still have no knowledge of the existence of the two check valves, and can only guess how much longer it would take me to sort out the mislabeling of the "Normal/Bypass" valve. Thanks again to each of you who contributed inputs and suggestions!

Best regards.

David

[Morich]

Quote:
It is sad to now realize, had I not simply accepted the labeling on the "Normal/Bypass" valve and verified the correct position at the very beginning, I could have saved myself over 12 hours of effort and a few bucks on parts, etc.

WOW!
That is hard to believe and I would guess that 99% of us would have also been wrong on that as the labeling seems to be so clear!!
I can't think of any possible way that could be anything other than the labels were put on wrong way back when built! I've tried turning things like the handle or the valve body and I just can't see any way it gets turned other than the label being wrong!

Sometimes the gremlins play tricks, other times they are just plain mean!!!!