Replacing thermostat and ECO on Atwwod 10 gallon HWH

[stugpanzer]

I was able to get the old thermostat and ECO off but to get the new ones on seems like a job. Someone told me the best way was to remove the plate in front of the tank. Instructions say to twist the plastic washer under the tabs....yea uh huh! Any suggestions would be greatly appreciated! Thanks!

[Old-Biscuit]

Using a small flat tip screw driver slightly 'lift' the three tabs outward just enough to cause a slight gap between tank and metal pan

Removing the 'pan' involves removing the seal rings on combustion chamber and on exhaust port.......NOT the way to do it just to install T_stat/ECO :S