Water heater issues

[Softshell]

Hi folks-
I own a 1994 Airstream Excella 1000. It has a standard Atwood 6 gallon water heater. The previous owner what looks like a home style thermostat control.
Because this is an add on I'm concerned it may be causing the water heater to overheat to the point where the pressure release valve activates and leaks water.

I have replaced the gas regulator and I have a new ECO Kit that hasn't been installed.

If you look at my attached photo you will see the add on to the left side of he photo.

Thanks in advance!

Mark

[HiJoeSilver]

It's common for the TPV to lift from time to time on rv water heaters. If there isn't a air bubble in the top of the water heater tank and water warms up it increases volume in a system with nowhere to go and the TPV will open a tiny amount to let a little water dribble out. Even mentioned in the owners manual for Atwood water heaters.