No hot water flow, stopped up ?

[MrWizard]

Atwood G6A-8E, RV 1997 Fleetwood Bounder 36S
The WH is in a sealed box next.to water bay, this is outside under the RV, no access to connections.at back of WH,
Water goes into the water heater , it does not flow out the taps, I.removed the drain plug and only clear clean water comes out, no sediment, leave drain open turn on water pump.lots of Clean clear water comes out,
When I turn Bypass valve to bypass mode, hot water taps have cold water good flow,
I.have tried compressed air into the hot water drain in an effort to clear any clog and flush the water heater afterwards, it did not work, I have done this to both HW and CW drains and lines taps closed water heater drain open, I'm.ready to buy a borescope to examine inside the wh to look at the HW outlet, also going to remove and look at the bypass valve, some pix.to explain







Last photo underneath RV looking up at the sealed box, metal covered with vehicle undercoat, the two flexible LP lines are visible, they goto WH & the rear furnace

I hope our resident experts can shed some light on fixing this, I'm hoping for.flex lines inside the box, so I can slide the water heater out, maybe it's a clogged check valve of some kind

Sorry about the photo size, I'm on my phone, not as easy to manipulate pages and photos

[dougrainer]

The ONLY reason a W/H would require a check valve is if it is part of the Bypass system, that uses a handle and not the 3 valves behind the Water Heater. YEARS ago, RV's built in California required the check valve due to state plumbing codes. Once California dropped this requirement for RV's they stopped installing them. The problem with Check Valves that are NOT part of the Bypass system is, the usually had a squealing/humming noise when water flowed thru them. National Motor homes(built in California) were the brands we sold and serviced. We would remove the check valves when customers complained about the noise. National were the ones to inform us about the California code that required that check valve. But since our customers were not in California, we could remove the check valve. I always use and tell people to use the BRASS CHECK VALVE when replacing a faulty check valve. In this case, if you HAVE a single lever Bypass valve, Odds are you need to have that valve installed to make the Bypass system work correctly. Doug

[lane_hog]

With all the generator advice Mr. Wizard has given over the years, it pains me to see him having this kind of trouble with something that shouldn't be this difficult to fix...

[schlep1967]

So much for creating easy access. If you do replace the check valve in the future, pay attention to the direction of flow arrow. It won't matter on the gutted one you have now but it will on a working one.
Did you find all of the old pieces of the check valve?

[MrWizard]

That wooden "wall" is the roof/top of the wh compartment, and is also the floor under the rear lp Furnace used for warming the bath and bedroom,
The perspective is from laying on my back under the RV, looking up at the enclosure ,
Task is complete, and this is the best hot water flow in several years,
The way it is installed, means no interior.storage space was appropriated , but it's ??the pits.to work on

[MrWizard]

It's more like a spring loaded trap door, that doesn't open all the way,
Opens about 40° instead of 90°, because the LP lines are in the way, and I have to hold it open, because I didn't cut it all the way through all the way across
But it Is Access
Hopefully I will never have to do this again ,

[Bobbo]

schlep1967 wrote:
Wizard, What is that wooden wall right behind your pic of the installed check valve? If you can access that from the other side, that would get an access panel added if it were my camper. That way when you get a replacement check valve, available at any Lowe's of Home Depot, you can easily replace it.

If you install a permanent access panel, I would opt for a shut-off in that water line and forgo the check valve. Change from a 1 valve system to a 2 valve system.

[JBarca]

Thanks for reporting back.

They sure buried that one deep inside never to be seen. Wow...

[schlep1967]

Wizard, What is that wooden wall right behind your pic of the installed check valve? If you can access that from the other side, that would get an access panel added if it were my camper. That way when you get a replacement check valve, available at any Lowe's of Home Depot, you can easily replace it.

[pianotuna]

I hope you will have an access hatch after all this effort!

[MrWizard]

I obtained limited access,
I made it work
The check valve was all plastic, a brass 90 between valve and water line


It's been gutted & cleaned and I'm going out to put things back together, weather forecast is rain for Monday starting about 3 am, so I want to finish this,
All the water and LP is turned off, got to put this back or cap/plug the water line

Back together her ready to test,

No LP leak, already checked for that, using the red stuff,

[JBarca]

MrWizard wrote:
What is the reason for the check valve in the output ?

Stop cold water being syphon into the tank when the water in the pipes cools after the faucet/shower has been turned off ?

I don't have a replacement, and unless its a safety reason, I'm not going to replace it, as long as it operates without it

I want max flow hot water !!

The check valve is part of the winterizing by pass kit. The bottom of the heater has 3 way valve, and the top has a check valve so the antifreeze will not go backwards into the heater and use up 6 gallons of antifreeze. Or 10 gallons if you have the bigger heater.

Here is the kit installed from Sunline.

You can see the brass check on top


The yellow arrow is pointing to the 3 way valve on the bottom.


This is another model then the one above. Same setup


During the heater unhooking process, you can see the white plunger in the check valve on the top fitting.


I myself do not like the check valve setup after having so many failures with them as the camper gets older. I restore older water damaged campers. Every heater I pull out gets a 2 valve bypass added to get rid of the plastic straight thread PEX fittings the factory used which leak as time goes on and eliminate the check valve.


This may not work in your case as you have no room for it at the back of the heater, just showing you so you know what it does.

I use brass machined hex nipples to correct the plastic straight running thread fitting issue, then remove the check and top Tee, and install a Flair-It 3 way valve. This becomes a 2 valve bypass setup.


You talked about removing the check, the system will work normally without the top check valve, the issue comes when you want to bypass the heater to add RV antifreeze.

Good luck on your cut and hassle project. I know they can be frustrating.

John

[wa8yxm]

MrWizard wrote:
What is the reason for the check valve in the output ?

There are 3 different types of water heater bypass systems
1 valve
2 valve
3 valve

All 3 have pipes in a sideways "H" pattern Or a wide capitol I if you have the proper font) The top line is usually red and is the HOT pipe
The bottom usually white and COLD The vertical pipe is the bypass and can be any color
On the 3 valve system the bottom is often white and the top red

On the 3 valve system the tank side of the bypass line has a valve in the hot and cold lines (one valve each) and ther is a valve in the bypass.. To USE close the bypass valve so the pipe and handle are like this + and open the other two (=)

To bypass. reverse that.

Next is the 2 valve system. these are 3 way valves
With the handle pointed towards or away from the heater.. USE
With the handles pointed either toward or away from each other BYPASS

Finally we have the single valve system
one 3 way valve in the cold line.. it either sends water into the tank or into the bypass.. but if it's sending water into the bypass what's to keep it from "Back filling" the heater via the hot water outlet?

The check valve of course

[larry_barnhart]

I removed our broken check value and everything was ok but I never winterized . chevman

[MrWizard]

What is the reason for the check valve in the output ?

Stop cold water being syphon into the tank when the water in the pipes cools after the faucet/shower has been turned off ?

I don't have a replacement, and unless its a safety reason, I'm not going to replace it, as long as it operates without it

I want max flow hot water !!

[MrWizard]

Jbarca,
Thanks for the pictures, I can pry the cover enough to peek inside and can see the line connected to the output at the top of the WH, the line has a plastic fiting with finger wings,.
But I can't get my hands in there yet, and was Not able to.get a picture , going to make another attempt shortly

Richard I hope your water heater is easier to get at.
Because
If you have a 36S like this one, your in for a heap of frustration,

I'm turning off the propane, letting the fridge burn it off, then use the angle grinder to cut the cover plate,
I don't have air tools & chisel, and the saw blade on the multi tool is not up to the cutting job on this steel plate
This should have been a simple job with minimum hassle,
It has been everything but that, with one obstruction after the other