Thermocouple, gas fired boiler, does gas pass through the copper tune??

[GFarra31]

Hi All,

Can you guys educate me on how the pilot and thermocouple work on a gas fired boiler? I have a Utica boiler.

There are 2 connections from the gas valve into the pilot assembly. I believe the thermocouple is the thinner copper tube and it screws into a port on the gas control valve.

Does gas flow through the copper tube into the pilot assembly? I always thought a thermocouple was an electrical device.

There is a second connection which looks like aluminum (silver in color, not copper) that I believe is for the pilot itself.

Thank you,

George

[kangaroogod]

The thermocouple as you referenced is a device that makes electricity when heated. This electricity powers a safety system in the gas valve to ensure the pilot is lit before turning on the gas. The copper thermocouple itself does not carry gas. Of course noone should be playing with gas unless fully qualified or BOOM!

'The more you know, the more you realize you don't know'

[ziggyhere]

The aluminum line supplies gas. The copper line is either reading millivolts for from the flame sensor or it supplies electricity to a spark igniter.

[GFarra31]

Thank you guys for the quick reply! i was confused because I was expecting to see a wired connector on the thermocouple instead of what looked like a very small supply line.

Regards, George