> Measure the length and buy a "universal replacement thermocouple" of
> the same or next longer length. The "universal" kit has all the required
> parts to connect it to virtually any gas valve and pilot ass'y.
Actually, it doesn't matter how long your replacement thermocouple is,
provided it's long enough to reach from the pilot light to the gas
valve. Thermocouples are like extension cords in that respect; you can
always use a longer one to replace a shorter one.
If it's a Friday night before a long weekend, and the only store in town
that's open has a 6 foot long thermocouple, you can still use it to
replace an old 24 inch thermocouple.
I just thought I'd clarify that point in case any newbies reading this
got the idea that you had to replace the thermocouple with one of
similar length. If you can get the same length as the old one, great.
But, any longer thermocouples will also work for you.