At 12:45 PM 8/5/2012, Leonard Sitongia wrote:
>the thermocouple.  I was wondering how to troubleshoot it.  Measure
>conductivity through it with it in hot water and ice water?  But, since

Thermocouples are by nature extremely low-impedance devices
(basically two wires twisted together).  I think (though I don't
know) that the ordinary gas-valve thermocouple is actually a
thermopile, i.e. several thermocouples in series.  The only practical
way for you and me to test them is to stick them in a flame and
compare their voltage output against a good one or against their
rated output.  Since they're active voltage generators, your ohmmeter
will be totally confused unless you get a lot farther into the
science of them than most people care to.

Yrs,
d