Atwood Water Heater T-Stat Question

Traver8 wrote:
Since some have responded with questions let me tell you the story and see what you think.

I am living in my trailer for work. Normally running the water heater on electric. Left town and found some strange conditions when I returned.

1. Water heater was left on and full.
2. Water supply was turned off.
3. My time away turned into two weeks.
4. When I returned And turned the water supply back on, I found that the hot side seems to be really empty - took a long time to fill and get the air out.
5. Water heater would no longer heat on electric, propane did seem to start and run.
6. I found signs that the temp/pressure relief valve had released some water..
7. When I removed the unit to check/change the electric element I found that the styrofoam cover was melted on the top of the tank.
8. Confirmed that the electric element was bad and changed it.
9. Now heated on both electric and propane but noticed the propane seemed to run poorly, restarting quickly etc.
10. While checking the t-stat electrical connection I noticed that the propane would stumble a starting and stopping quickly.
11. Used my IR thermometer to try to check water temp. found it to be hotter than I would expect with the normal T-stat and believed that the ECO was stopping the heating.
12. Finally managed to reseat the t-stats and get things running correctly again but want to try to reduce the chance that this will happen again.

Anyone want to render an opinion on my conclusions?

Thanks,
Terry

Sure thing...

Do NOT leave water heater ON (electric or propane) when away and with water supply valved out.

Doing so created your issues.
Water temp slowly dropped so t-stat called for heat...element heated water and then t-stat secured heating.
But over time (2 week period no water supply) water in WH tank absorbed the air pocket and then dissipated via weeping T&P Relief valve until lack of water level caused tank to start getting hot from heating cycles.
Normal t-stat continued to function controlling heating cycles otherwise the ECO would have shutdown heating and 'locked out' any further heating (Red Fault Light ON----has to be reset by turning ON/OFF switch OFF then back on before more heating could occur)

Don't see where you had the Fault light and had to reset it.


SO.....
DON'T Leave WH ON w/o water supply ON and unattended for days/weeks.