I think this is the newsgroup traditionally used for appliance questions, so
hopefully this is acceptably on-target.
The Kenmore-branded Whirpool dryer (110.79912900) hasn't been doing well in
recent months, taking unacceptably long to dry loads while still clearly
putting out some heat. Obviously, the first thing I did was to pull the
skins, clean out the usual amount of congealed lint inside the filter screen
area, and leaf-blower the entirety of the interior. Happily it is right up
against the exterior garage wall with a real short duct to the outside, and
that is totally clean.
I observe that when started, the igniter comes on, I get a nice flame for
three or four minutes, and then it goes out. But unlike the typical (as I
understand it) coil failure, the process repeats, but not for several minutes.
No wonder the drying takes so long - the gas should be burning considerably
more frequently than I'm observing and it's thus blowing lukewarm air for much
of the cycle.
I first thought that this still could be an issue with the coils, and found a
web site that tabulated typical resistance values to the various combinations
of terminals on the three-post and two-post coils. To my surprise, all were
dead on. So I assume the coils are fine.
So now it's time to ask for some assistance. My next thought is the pair of
thermostats inside. I haven't pulled them or tested them in any way yet, as
they're harder to reach than the coils. Is this a valid next step? Would it
be most likely the low-temp (155 degree) thermostat not reacting quickly
enough to the drop in temperature after the flame has been turned off?