Basic question about Atwood heater

[Jennparker2001]

Hi,
I’m a very new RV owner and we were given a ‘94 Dutchmen 26TB that was sitting in a field for a few yrs. Bit by bit we’re repairing and learning about the unit as we go. I have a basic question about the Atwood water heater. I see two open pipes on the bottom of the unit (one on each side) on the inside of the trailer and I’m wondering what those are for and if I need to connect something or cap them? Can anyone identify the purpose of these two tubes?The photo shows one tube on the lower left corner.
Thanks!
Jenn

[franktafl]

Is the heater connected to anything?

[Jennparker2001]

Yes everything seems to be connected just two pipes pointing out of the bottom seem to be disconnected. Would more pics help?

[Jennparker2001]

Looking at the Atwood manual I found online I believe it might be for what they call ECO T Stat. Part 18 in the diagram below. Part number 91873.