No hot water

boba wrote:
nomad yes thats the set up and i am afraid it is a bad/clogged mixing valve--ugh

It's not that big of a deal. Take off the mixing valve and soak it in some clr for an hour then rinse it with fresh water. Then on the end of the plastic cap you will see an Allen screw that is filled with a plastic resin. Pry the resin out with an awl or something similar. Then remove the Allen screw. Take the cap off (all it does is lock the setting on the temperature valve). Turn the valve back and forth while trying to keep the setting close to where it was originally. Put it all back together and you will be able to take a nice hot shower. I am assuming that before you go through this that you made sure that your outside shower faucet was off, as that is the most common cause for lukewarm water.

I have checked and triple checked the outside faucet. It is closed

outside shower hot water valve in open position, without spray nozzle being depressed?

nomad yes thats the set up and i am afraid it is a bad/clogged mixing valve--ugh

boba wrote:
there is also a chrome (i will call it a T valve on the balk of the heater) valve and of course an inlet and an outlet.

This sounds like a tempering (mixing) valve to me. Does it have two inlets and one outlet?

Bruce

DO you have an Atwood XT Model?

IF not an XT Model....no mixing valve

i have one valve for bypass that stops all water from entering the heater. looking at the back of the heater i could see one other valve(yellow in color if that makes a difference). i believe that the mixing valve was replaced once under warranty. i do not know if they could access from underneath or took out the heater(which is probably easier than taking out the toilet). there is also a chrome (i will call it a T valve on the balk of the heater) valve and of course an inlet and an outlet. i could not reach the yellow valve(again without taking out the toilet). i was hoping that opening and closing(or vice versa) would loosen it. i did winterize, but the only valve was the bypass that i turned--the tank was then drained and plug returned with only one turn(which would not seal the opening) i have an outside fauce and it is closed.

Describe your bypass valve system
1 Valve.. No it's not that valve, it is a different valve
2 Valve.. No comment
3: Valve: might be the outlet valve closed.

3 valve systems I will call them top (HOT) middle (Bypass) and bottom (Cold)
You must have the hot and cold valves open and the bypass closed. Also check all showers to make sure the mixing valves are closed.. A common fault is the outside shower cut off at the shower head but the mixing valves left open allowing cold water to bypass via the shower.

Single valve (Actually there are not single valve, just single handle) systems have a 2nd hidden valve.. NOTE That this valve MAY exist on all 3 systems, it is an outlet check valve,, It is the very first thing coming off the heater tank.. In many cases this valve will "Gum up" and stick closed. I have both seen and heard of cases where this valve stuck closed..

One camper I know of simply gutted the valve (Pulled the parts out of the inside using needle nose pliers, they winterize by the dry method so they did not need it.. The valve can be next to impossible to get off the heater.

IF this is your problem, and you wish to retain check valve function, Then gut it as they did and install a 2nd check valve (Plumbing or hardware supply stores) or install a quarter turn valve.

Thanks the mixing valve was my guess. Was hoping for a quicker easier fix I did check all faucets to make sure they are off. Unfortunately itis a bigger job than I want to attempt before next trip. Might be easier to remove heater to replace mixer than to remove toilet and still only have a small opening to work through. Thanks to all for responses

The 'bypass allows water to go around water heater and connect to hot water plumbing lines.

BUT it doesn't necessarily stop cold water from going into water heater...depends on how bypass is installed.
Some use 3 way valve on cold inlet......turned one way water goes to WH. Turned 90* water doesn't go to WH and bypasses
Some use a cold inlet valve and a bypass valve.......both have to be turned.
If cold inlet is open and bypass is open...cold still goes in WH and also bypasses WH.


Do you have an outside shower?
If hot/cold knobs are open and shut-off on handle is closed hot/cold will mix in shower faucet causing no hot water.

Doesn't sound like you previously have gone to the trouble of changing valving on WH as you state you have to remove toilet/panel to access WH.

Mixing valve is a possibility IF (Big IF) you have an Atwood XT Model WH.
If you don't have an XT Model (extended capacity by heating water to higher temp and regulating output temp via mixing valve on WH) then cold water in hot water lines is only possible with incorrect valving or shower not shutoff at knobs.

If you have an Atwood XT model.....then mixing valve hit side is clogged up and not allowing hot flow just cold.