Atwood GE16EXT Water Heater Mixing Valve Failure

[rockintom]

Thought I bring this thread from Excel forum to see if we could get a little more exposure. Hope someone could help us understand the root cause of failure. Thanks! Atwood hot-water heater mixing valve

[RV Wizard]

The owners manual states that these valves need to be removed and soaked in white vinegar to dissolve any scale that may build up; binding the internal mixing mechanism on an annual maintenance program. One way around having to do this would be to have a good filter and softener system treating the incoming water supply.

[jcthorne]

Quote:

Originally Posted by rockintom Thought I bring this thread from Excel forum to see if we could get a little more exposure. Hope someone could help us understand the root cause of failure. Thanks! Atwood hot-water heater mixing valve

The root cause of failur is the mixing valve stem gets stuck. Adjusting the valve full open and full closed and back someties works it free and the valve work fine from there. Sometimes its stuck too well and replacement is needed. The antifreeze used may have something to do with it but the root cause is the same. Its stuck.

FYI its not necessary to pay Atwood $260 for that valve. Its not even a part manufactured by Atwood. They are common domestic hot water mixing valves. I have one from Watts that is fully adjustable and only paid about $40 for it from drillspot.com (Grainger). Just look for one with 1/2" npt connections. Since all the lines are flex hoses anyway, slight differences in size and shape of the valve do not matter much.

The Watts mixing valve can also be used to upgrade a standard Atwood water heater to a much larger capacity 'exotherm' equivelent if you feel the need for more hot water in your coach.

[Luv2go]

Quote:

Originally Posted by jcthorne I have one from Watts that is fully adjustable and only paid about $40 for it from drillspot.com (Grainger). Just look for one with 1/2" npt connections. Since all the lines are flex hoses anyway, slight differences in size and shape of the valve do not matter much.

You would not happen to remember the part number for that valve? I can't find a "mixing valve" at Drillspot from Watts (probably searched wrong).

[rockintom]

Quote:

Originally Posted by RV Wizard The owners manual states that these valves need to be removed and soaked in white vinegar to dissolve any scale that may build up; binding the internal mixing mechanism on an annual maintenance program. One way around having to do this would be to have a good filter and softener system treating the incoming water supply.

First of all thanks for all the responses! Good info.

Mike,

I have looked at my owner's manual closely and don't see anything referring to R&R and cleaning the valve in vinegar. The owner's manual simply gives reference to not tampering with it and it must be replaced as an assy. by a Certified RV tech. Also gets all the scalding precautions. Can you post the owner manual info that you're referring to?

The reason I even posted was because one of my engineering friends is insistent that the root cause is related to an RV antifreeze or winterizing issue, because many/most of the seizing of the valve is noticed after dewinterizing.

And I contend that the issue happens when hard water/mineral build up are allowed to "set" for awhile unused.......the valve gets stuck and the next time its used it's stuck and thus you get cold water. My deal that if the unit is winterized properly, that antifreeze is not the root cause. We have had 2 rigs with this set up for 6 years now....and I've never had a problem with our mixing valve. Both rigs have had nothing but soft water (Travelsoft) run in them. Of course, as FTers, we have never winterized either!!Our rig have never set for more than 2 weeks without use.

I've followed your post for quite some time and have always respected your knowledge on many RV issues, so really appreciate your contribution on this one. Help settle this little disagreement. Do you think anifreeze or the winterizing procedure are the root cause of failure? Thanks! rockintom

[rockintom]

Quote:

Originally Posted by Luv2go You would not happen to remember the part number for that valve? I can't find a "mixing valve" at Drillspot from Watts (probably searched wrong).

I searched "tempering valve" then Watts on the left side of the page....then picked this one....cause it had 1/2" fittings. Watts 70A 1/2 Tempering Valve A bit more expensive than discribed....but a hellva lot cheaper than $260!!!!
rockin'

[rockintom]

Quote:

Originally Posted by rockintom I searched "tempering valve" then Watts on the left side of the page....then picked this one....cause it had 1/2" fittings. Watts 70A 1/2 Tempering Valve A bit more expensive than discribed....but a hellva lot cheaper than $260!!!! rockin'

I just noticed that the valve I posted above is a "sweat in" connection.....this one is more what you'd use.....but again a bit more expensive. Watts 1/2 MMV-PEX Tempering Valve

[RV Wizard]

If you are going to winterize a coach, I highly recommend the wet method for this very reason. If the water system has had water with minerals, the walls of the water lines will allow the minerals to accumulate and then if you only blow out the lines to winterize, the minerals just dry out and give you all kinds of problems.
I doubt very seriously that the potable antifreeze is the root of these valve failures. Otherwise, I would have found many, many more failures on our stock units when de-winterized and checked out for deliveries.
It was a long time ago that I read someplace that the maintenance of these units included this R & I of valves and cleaning. I will see if I can find it again. It may have come with the new valve installation instructions.

[jcthorne]

My memory is not what it was. I had the price right but the vendor wrong. Drillspot does not have the 1/2" threaded version of the 70a tempering valve. I had ordered it from PexSupply but it was under $40! Currently $36.85

0215473 - Watts 0215473 - 1/2" L70A-T Lo-Temp Threaded Tempering Valve (100°-130°)

It works very well.

[rockintom]

Quote:

Originally Posted by RV Wizard If you are going to winterize a coach, I highly recommend the wet method for this very reason. If the water system has had water with minerals, the walls of the water lines will allow the minerals to accumulate and then if you only blow out the lines to winterize, the minerals just dry out and give you all kinds of problems. I doubt very seriously that the potable antifreeze is the root of these valve failures. Otherwise, I would have found many, many more failures on our stock units when de-winterized and checked out for deliveries. It was a long time ago that I read someplace that the maintenance of these units included this R & I of valves and cleaning. I will see if I can find it again. It may have come with the new valve installation instructions.

Thanks Mike......it makes perfect sense to me. Regarding the R&I of the valve for an annual cleaning is still hard for me to swallow as on many of the floorplans that Excel (PI) builds....that means a complete removal of the entire water heater. I'd still would be interested in seeing the information on that. Thanks again, as you reconfirmed what I thought. Somehow or another I'm gonna get a few drinks and a meal out of this deal!!!! rockintom

[Luv2go]

Quote:

Originally Posted by jcthorne My memory is not what it was. I had the price right but the vendor wrong. Drillspot does not have the 1/2" threaded version of the 70a tempering valve. I had ordered it from PexSupply but it was under $40! Currently $36.85 0215473 - Watts 0215473 - 1/2" L70A-T Lo-Temp Threaded Tempering Valve (100°-130°) It works very well.

Thanks

[Jim & Bona]

Quote:

Originally Posted by RV Wizard If you are going to winterize a coach, I highly recommend the wet method for this very reason. If the water system has had water with minerals, the walls of the water lines will allow the minerals to accumulate and then if you only blow out the lines to winterize, the minerals just dry out and give you all kinds of problems. I doubt very seriously that the potable antifreeze is the root of these valve failures. Otherwise, I would have found many, many more failures on our stock units when de-winterized and checked out for deliveries. It was a long time ago that I read someplace that the maintenance of these units included this R & I of valves and cleaning. I will see if I can find it again. It may have come with the new valve installation instructions.

RV Wizard,

Here's my story on a mixing valve failure. I winterized my coach by first draining all water lines and the water heater. I then blew out the system with compressed air, regulated to 40 psi, at the city water in-line. Finally, after assuring myself that the water lines were all blown out and that the water heater was completely drained, I poured something like 6-7 gallons of the red anti-freeze into the fresh water tank, which had already been drained. After replacing the water heater drain plug I pumped anti-freeze through the system. However, I did need to add another 4 gallons of anti-freeze to fill all the lines. I suspect that I was partially filling the hot water tank with all that anti-freeze.

You mention de-winterizing stock units. Would the water lines and heaters in these units have been full of water before winterization - new or used RVs (might be a dumb question)? The reason I ask is that I suspect that water remained in my mixing valve even after winterization, thus frozen water in the mixing valve resulted in the failure. Unfortunately I didn't attempt any cleaning or other repair of the valve as it was replaced under warranty.

Background information on my failure and exposure to high mineral content water follows:

1. The valve failed to operate properly immediately after the first, and only, dewinterization of our coach.
2. When the coach was winterized it was four months old (from date of manufacture) and had been used six weeks at one private RV Park with no apparent hard water issues.
3. Since the time the valve was replaced we have lived in the coach full time 2 1/2 years. We have travelled and stayed in 25 states and 6 Canadian provinces/teritiories, including Alaska. Water conditions have ranged from softened water to mineral content so high that the water turned black when it went through the water heater. I'm sure our system has been exposed to plenty of lime, calcium, and iron as I've needed to chemically clean the fixtures several times.
4. The replacement mixing valve is still working fine even after 2 1/2 years of exposure to some of the crummiest water in North America.

Jim

[RV Wizard]

Quote:

Originally Posted by Jim & Bona RV Wizard, Here's my story on a mixing valve failure. I winterized my coach by first draining all water lines and the water heater. I then blew out the system with compressed air, regulated to 40 psi, at the city water in-line. Finally, after assuring myself that the water lines were all blown out and that the water heater was completely drained, I poured something like 6-7 gallons of the red anti-freeze into the fresh water tank, which had already been drained. After replacing the water heater drain plug I pumped anti-freeze through the system. However, I did need to add another 4 gallons of anti-freeze to fill all the lines. I suspect that I was partially filling the hot water tank with all that anti-freeze. You mention de-winterizing stock units. Would the water lines and heaters in these units have been full of water before winterization - new or used RVs (might be a dumb question)? The reason I ask is that I suspect that water remained in my mixing valve even after winterization, thus frozen water in the mixing valve resulted in the failure. Unfortunately I didn't attempt any cleaning or other repair of the valve as it was replaced under warranty. Background information on my failure and exposure to high mineral content water follows: The valve failed to operate properly immediately after the first, and only, dewinterization of our coach. When the coach was winterized it was four months old (from date of manufacture) and had been used six weeks at one private RV Park with no apparent hard water issues. Since the time the valve was replaced we have lived in the coach full time 2 1/2 years. We have travelled and stayed in 25 states and 6 Canadian provinces/teritiories, including Alaska. Water conditions have ranged from softened water to mineral content so high that the water turned black when it went through the water heater. I'm sure our system has been exposed to plenty of lime, calcium, and iron as I've needed to chemically clean the fixtures several times. The replacement mixing valve is still working fine even after 2 1/2 years of exposure to some of the crummiest water in North America. Jim

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