Community Forums

TexasTwoStep · 12-02-2016, 06:38 AM

Our hot water is not as hot as it used to be. I'm thinking the water heater is scaling from out travels west and needs a vinegar treatment. I'm lazy and haven' checked the voltage because the surge protection would shut power off if low. Am I overlooking anything?

drfife · 12-02-2016, 07:33 AM

Possible mixing valve failure.

rockintom · 12-02-2016, 03:04 PM

Spot on Doc. Gary I just made a recent post on this issue.

hayward3411 · 12-02-2016, 05:34 PM

X2 on mixing valve, had to replace mine due to calcium buildup when it was 2 years old.

TexasTwoStep · 12-03-2016, 05:41 AM

Well I opened the hwh yesterday and it was badly scaled. By noon I had 8 gallons of vinegar in it and was letting it marinate overnight. This is such a p-i-t-a job that I have been delaying it for about a year, so I had the vinegar on hand. Plan on putting it back in order this morning. Will then be able to determine if that fixed it. I didn't know there was a mixing valve other than at the faucets?

rockintom · 12-03-2016, 07:10 AM

Gary here's my post I was referring to. http://www.irv2.com/forums/f116/just...ry-312772.html

Also the RV Geeks did a WH cleaning procedure video. It's Suburban but the main subject would be the same as Atwood.

https://www.youtube.com/watch?v=TL7AtXJYNcc

rockintom · 12-04-2016, 11:03 AM

So how is it going Gary? I talked with Gary and had him do a boil-out job on the mixing valve. rockin'

TexasTwoStep · 12-05-2016, 05:09 AM

Did the boil out procedure Tom outlined and everything works fine. One thing Tom advised me on the phone that isn't in the above outlined procedure is to be sure and count the revolutions on the adjuster so you can get it back to it's original position. Thanks Tom and everyone else for your replies

YC1 · 12-05-2016, 06:25 AM

Gary, what "adjuster" are you referring to?

rockintom · 12-05-2016, 08:26 PM

Quote:

Originally Posted by YC1

Gary, what "adjuster" are you referring to?

Since Gary hadn't answered yet, I'll try to explain. The mixing valve is on the back side of the Atwood water heater. According to the manufacturer the valve is set to the proper temp (120*F) at the faucet and then sealed. I have found that you can take a sharp device (putty knife or pocket knife) and pop off the dark grey hard plastic cap cover. This will expose a phillip's headed screw. After removing the screw you can remove the large grey plastic cover that locks the adjuster nut (11MM). Make note of the location of the adjust nut so you can go back to that temperature setting. After boiling the valve as already outlined you can move the adjuster screw in and out (about 5 complete turns from end to end) every 15 minutes of boiling. When done the adjuster nut should be moving in and out freely (mineral deposit broke loose). Go back to the original setting and reinstall the cover and screw. Reinstall valve on back of heater.

Note: I found my adjuster was set from the factory about 1.5 turns in from the end of travel when turned counterclockwise. Hope this answer your question. rockin'

Max1 · 12-06-2016, 03:19 AM

Texas,
Do make certain your outside shower faucet is in off position, hot and cold closed as leaving them open for some reason will cause a similar problem such as you've described. Should you need a new valve I have had good luck with this one 0559130 - Watts 0559130 - 1/2" LF70A-T Lead Free Threaded Tempering Valve (120° -160&#176

YC1 · 12-06-2016, 04:31 AM

Thanks Rockintom. Must be an interesting looking device. I had my HWH out to replace the check valve and never noticed that.

Are you sure it is a "mixing valve" and not a thermostat?

rockintom · 12-06-2016, 04:46 AM

YCI,

Yours may be a Suburban. The check valve in this WH is inside the mixing valve. It's a mixing valve on an Atwood XT series WH. It's a 10 gals capacity tank with 16 gals of 120*F water at the faucet. That is achieved by using a mixing valve that mixes the approx. 160*F superheated water in the tank with tap water to give the 120*F at the faucet. Thermo and ECO switches are on the front of tank. rockin'