I put a new transducer on and I have no temp reading, plug it in on my other helix 9 it shows temperature. Went to the setting and there is not option for temp. Anyone help me figure out why one unit is reading temp and the other is not?

Did you select the same transducer on both units? One letter difference can change everything.
Also, go to the network sources page and make sure your temp settings are showing from the graph it's connected to.

There not network together. GN1 units.

Gen 1 Helix 9s can network. But I think the transducer selection is the answer.

First Make sure your unit is running the most recent version of software, if so then
Using the Setup Menu tab, set all features to "Auto" or "Restore Defaults." If that doesn't fix it most likely your tranducer...if you know some that has the same helix gen 1 test your head unit on theirs..I had the same issue on that helix gen1 and it was bad transducer..but the above were steps humminbird advised to troubleshoot

Used my other helix 9 and water temp is working tell me it’s a setting. Thanks for the input.

The Temp setting is gone even in select read out. I did the restore defaults still nothing.

Been a while since I had a helix but might try making sure the unit is in advanced mode then go through the settings,