I suspect the over heat switch is set and you have a warming value
or the warm value of the switch has resistance.

I have some thermal switches that have coils that heat in series and
once hot it shorts out the coil. Resistive wire that heats the bi-metal.

Try putting an ice cube in the bucket - then towel it out. It might
be cold enough to reset the contact set(s).

Might be the contact set is getting pitted and takes a full cool to
really press hard.

Martin

Ivan Vegvary wrote:
Have had this popcorn machine (theater type, medium size) for about 15
years now (got it used). Unable to make a second batch of popcorn.
First batch: turn on the heater, add oil, add popcorn, wait and get
about 99% to pop.
Second batch: Dump first batch, (heater switch still on) immediately
add oil and corn, wait and get ONLY about 30% to pop.
Third batch: Same as second.

Machine consists of cast aluminum pot, disc type heater (electric)
bolted to the bottom, an in-line thermostat about the size of a pack of
chewing gum. Manufacturer very helpful, we're on our third thermostat.
No difference.

Question: What would make a heating element (solid disc, about 5 in.
diameter) act intermittent. It is very similar to the heating coils on
an electric stove. I would think if it comes up to temperature once, it
should be alright. There are no moving parts within the heating
element. It is probably simply just a giant resistor.
The vendor is out of ideas short of selling me a new heating element
(expensive, but I'll buy one if indicated). In his 30 years of
experience all he has sold was thermostats, or, heating elements when
they were 'open' and wouldn't heat at all.

Any and all ideas appreciated. I loan this popper out to charities all
the time and therefore need it.

Ivan Vegvary