A water temp of 140 degrees results in water dripping from the pressure relief valve. Replacing the fixed temp thermostat with an adjustable one allows you to lower the temp, eliminate the leaking and save a little propane as you are no longer heating the water to temps that are not directly useable.
We have ours set to 120 degrees which is more than enough for showers and dish washing.
Installation takes about 10 minutes including reading the instructions. Cost about $40 including shipping.
I ordered from Marks RV. However you may find the part for less by Googling for “adjustable thermostat for Atwood”. Marks part number is A93105. Scroll way down to see it.
Here's a link to a Youtube video on how to install the Atwood adjustable thermostat: