What is this item on a Gravity System???

Kerr

What is this red item and how does it work??? Thanks!

Canucker

That looks like an old Honeywell Heat Generator. You can find an explanation on how it operates on the main page. If it hasn't been touched, that thing should have a lot of mercury in it
https://heatinghelp.com/heating-museum/mark-c-honeywells-patent-for-a-new-type-of-tee/

Kerr

Thank you...I believe you are correct...I couldn't remember enough about it to remember where to start! Thanks again!

JUGHNE

There is a story about that mercury heat generator that should be in the "Heating Hell" category.
Some one had one spill one floor up IIRC. Whole house ceiling turned into a very expensive toxic clean up project.

It could probably be safely cut out and carried out of the basement for disposal.