Discovery: Hot water not very hot!

[dcfleetwood]

So recently I noticed the hot water to be more on the warm/hot side and not as hot as it used to get. I was using it on electric so I switched it to propane and it appears to be doing the same thing. I remember reading somewhere about the mixing valve and have searched for that topic which I can't seem to find. Am I on the right track? and how do I test the valve or what does the group recommend I do first?
Thanks in advance!

[wolfgolden]

First step is to ensure the outside shower valves are off. These will mix hot and cold for meh water temperature.

[Old-Biscuit]

Brand/Model of WH?

Atwood uses a Mixing Valve on their 'EXT' models....standard models do not have one
Mixing valve is located on backside of WH Tank

Suburban doesn't use one on any model

Luke warm water:
WH Tank Bypass leaking thru/not closed
Mixing Valve (if equipped) hot inlet clogged
Shower turned off via button/lever on handle vs closing the hot/cold knobs
T-stat opening too soon/failing

[Tha_Rooster]

Originally Posted by dcfleetwood

So recently I noticed the hot water to be more on the warm/hot side and not as hot as it used to get. I was using it on electric so I switched it to propane and it appears to be doing the same thing. I remember reading somewhere about the mixing valve and have searched for that topic which I can't seem to find. Am I on the right track? and how do I test the valve or what does the group recommend I do first?

Thanks in advance!

No way to test valve you need to eliminate other possibilities first. Mine was clogged so a good chance your 2007 is also. Once you get removed you can simply clean out. The adjustment knob is in a fixed manufacturer position but can be adjusted if you want real hot water I did mine. Disclaimer before someone chimes in you could get water burned if adjusted to hot.

[Gary RVRoamer]

A 2007 Discovery is very unlikely to have an Atwood XT water heater, but check the heater model number to be sure. If not an XT, no heater mixing valve.


More likely the problem is one of these items:

1. Outside shower faucets are open, allowing hot & cold to cross-mix thru the outside shower/sprayer
2. Inside show faucets are open with water turned off at shower head. This also allows cold & hot to mix.
3. The valve for the heater winterization bypass is partially open, allow some cold water to bypass the heater and feed directly to the hot line.bypass valve

[Flyer15015]

Dave,
When is the last time you gave your hot water heater tank a good vinegar bath ?

You might be due.
.
Pull the pressure relief valve and check the rod for white stuff (calcium).

Lots of YouTube videos on how to clean the tank.

That's where I would start.

Mike in Colorado

[dcfleetwood]

I have a Atwood GE16 EXT, I checked the outside valves and the bypass valve and all checked ok. I didn't think this model had a anode rod per my research. Sounds like most are highly recommending that I clean it out with vinegar, which I will do soon. We're fulltimers so I have to plan it out. Thanks again for all the replies!

[mrboyer]

Originally Posted by Gary RVRoamer

A 2007 Discovery is very unlikely to have an Atwood XT water heater, but check the heater model number to be sure. If not an XT, no heater mixing valve.


More likely the problem is one of these items:

1. Outside shower faucets are open, allowing hot & cold to cross-mix thru the outside shower/sprayer
2. Inside show faucets are open with water turned off at shower head. This also allows cold & hot to mix.
3. The valve for the heater winterization bypass is partially open, allow some cold water to bypass the heater and feed directly to the hot line.bypass valve

Our 2006 Fleetwood Expedition has a mixing valve. Failed 2 years ago. Tried to clean. Replaced with one found on Amazon about half cost of one from Atwood.

[Old-Biscuit]

Originally Posted by dcfleetwood

I have a Atwood GE16 EXT, I checked the outside valves and the bypass valve and all checked ok. I didn't think this model had a anode rod per my research. Sounds like most are highly recommending that I clean it out with vinegar, which I will do soon. We're fulltimers so I have to plan it out. Thanks again for all the replies!

That one HAS the Mixing Valve and the Hot inlet from tank is clogged so only a little hot is getting into the valve
*T-stat allows heating to 160*F then Mixing Valve controls output to 130*F

You will need to remove the Mixing Valve and clean it, clean out the check valve and inlet screen



https://techsupport.pdxrvwholesale.c...twood-g16-ext/

[Tahoetom]

I agree with Mike from Colorado, I always try the simplest and cheapest way first. You don’t say the age of your rig but calcium buildup in the bottom of the heater will cause it to operate inefficiently.
Small price for a 12 inch wand, let the water cool down, release the pressure and pull the drain plug. Attached a hose to the wand and blast away, finished up with the suggested vinegar rinse.

Good luck.

[RichKimball]

Originally Posted by Gary RVRoamer

A 2007 Discovery is very unlikely to have an Atwood XT water heater, but check the heater model number to be sure. If not an XT, no heater mixing valve.


More likely the problem is one of these items:

1. Outside shower faucets are open, allowing hot & cold to cross-mix thru the outside shower/sprayer
2. Inside show faucets are open with water turned off at shower head. This also allows cold & hot to mix.
3. The valve for the heater winterization bypass is partially open, allow some cold water to bypass the heater and feed directly to the hot line.bypass valve

More LIKELY than unlikely to have an EXT model. Even my '08 Bounder has an EXT model. Oh well.

[dcfleetwood]

So I purchased a cleaning wand and OMG what a lot of white stuff came out, after that I replaced the mixing valve and all is back to normal. I still am planning to vinegar the tank when it works for us, but for now we're back in business. Thanks for all the replies!

[2psquared]

Does this have a check valve

[dcfleetwood]

Not that I'm aware of, just the mixing valve which is what resolved my issue.