Attwood mixing valve

[StewB]

I have a Attwood water heater with a mixing valve. It appears the mixing valve has malfunctioned. We get a short shot of hot water then cold every time we turn on a hot water tap. Has any one tried to take one of these apart to try and correct this? Replacment is $285 Can$ so if I can tinker with it and make it work I would save some cash.
Thanks for any input
Stew

[jrnymn7]

Why not have both... drink the beer, bottle what comes out the other end (fume wise), and run the boat with it! 🙂

[StewB]

Pulled the tank and removed the valve. Took it apart. Not realy scaled up but cleaned and polished surfaces with scotchbrite pads. Didn't have to drill the glue on the adjuster knob it was brittle so I just picked it off. Left glue off so now the valve is adjustable. Only thing I could find was the hot water inlet valve was sticky. Put it all back togeather and it works fine and is adjustable.
Saved a cool $285 that can now go to beer or boat gas.:)

[StewB]

Thanks all for the input and advice.
As stated just bypassing it could be dicey as the water is very hot without the mixing valve. I like the adjustable t-stat idea but using hotter water and a mixing valve resultes in more usable hot water.
I will pull it, and take is apart and clean it up. If that doesn't work, go to plan "B" and buy a differnt type.

[Clay_L]

One other thing to check is that the external shower valves are closed along with the wand valve. If the faucets are open you can get a cold water cross feed that yields some strange symptoms - often similar to what you described.

[Old-Biscuit]

katysdad wrote:
If you do away with the mixing valve be careful of water temp. I think this water heater uses a hotter thermostat than the reg unit. This way you get hot water for a longer period of time. The valve should reduce the water to a safer temp when working properly.

Correct........

Atwood normal t-stat 140*F and ECO (high temp) t-stat 180*F

Atwood XT (mixing valve model) normal t-stat 160*F then mixing valve is set for 130*F and ECO t-stat still at 180*F


Atwood does have an adjustable t-stat to replace preset 140*F t-stat
Adjustable from 110*F to 150*F

[katysdad]

If you do away with the mixing valve be careful of water temp. I think this water heater uses a hotter thermostat than the reg unit. This way you get hot water for a longer period of time. The valve should reduce the water to a safer temp when working properly.

[jrnymn7]

I run vinegar thru my entire system every fall and spring.

I used one of these, just in case, but generally I heat the water to only 104F, or so, and only when I need it for showering:

Mixing Valve $45 can.

[hardint]

We had the same deal on ours,Google Atwood mixing valve first,I pulled water heater removed valve,dissembled cleaned and reassembled. I also drilled the tamper proof glue from the handle so I can adjust the temperature to suit Me and re piped so I can adjust from an access hole now.
I'm sure the SAFTEY POLICE on here will scold me but be advised it's My Rv and Stewb asked for advise !!!! Not a horrible job except the white putty sealing the unit to the rv. Be sure to have some on hand before the task I did not !!!

[Old-Biscuit]

JPeyton wrote:
285? lol that's some valve. Worse case I would by pass the mix and just run the hot to the faucet, along with cold to the faucet and mix it the old fashioned way: yourself!

.

A bit more involved....but one could do a replumb and t-stat change out

OP

Deposits build up in hot side of mixing valve can clog it up.

Yes can soak it in 'CLR' or HOT white vinegar to clean and then rinse thoroughly.

Due to mfg. tamper-proofing (glued allen head screw) the knob to adjust output temp is pain to remove. Sometimes you need to move adjustment back & forth to clear. In order to do that you have to remove glob of glue to get to screw that holds knob in place. When freed knob can be mated with adjustment splines


IF that doesn't work..........replace with a 'residential' mixing valve by WATTS. Just need some nipples for new valve and a LOT less expensive..........LINK

[JPeyton]

285? lol that's some valve. Worse case I would by pass the mix and just run the hot to the faucet, along with cold to the faucet and mix it the old fashioned way: yourself!

[katysdad]

I have taken mine apart and cleaned it and it seems to work fine.