Very old Wall Furnace

[josefbrunclik]

This is 40 year old wall furnace that has been condemned. My question is, if you guys look to the left of the gas valve, you can see a copper coil. Anybody have any idea what this may have been for? It is not connected to anything. Could be be some old temperature limit device?

[Firebird A/C]

Is the gas line to the wall furnace ran in copper?

[mike3]

I'm thinking that is a left over coil from a hydraulic thermostat on a gas valve. The coil reacts to temp and the gas valve responds.