The thermocouple on my 7yo Whirlpool water heater went out Sat. The stores open
on the weekend had only right hand thread thermocouples, and as far as I could
find out, the manufacturer would sell me a conversion kit for $31 which would
take 10 days to receive. (out of warrantee)
My solution: I carefully clamped the threaded fitting on my old thermocouple
end-to-end in my vice so one face was up, then used a 1" cutting disc in my
dremel tool to cut a slot into the fitting so I could slide it off of the tube.
I slid the threaded fitting on my new thermocouple down out of the way, then
slipped the slotted one over the tube and carefully screwed it into the valve
fitting. It works perfectly.
If you have a several years old Whirlpool or American Products water heater, you
might want to check to see if it has the left hand thread on the thermocouple.
If it does, and it is still in warrantee, contact the manufacturer now so you
can get the conversion kit for free ahead of the time you really need it.
The early symptom of failure on my thermocouple is that it took 1 1/2-2 minutes
of holding down the pilot light to get it to re-light and stay lit. The new one
took about 20 seconds.