Kiln Sitter Trouble
Shooter
The Kiln Sitter Fails To Shut Off
Probable Causes:
■
The cone is sticking to the cone supports. This pre-
vents the cone from sagging properly.
■
There is no play between the trigger and the release
claw.
■
The actuating rod is not centered in the porcelain
tube.
■
The kiln is not level.
■
The wrong cone was loaded in the Kiln Sitter.
If the Kiln Sitter does not shut off when the weight
drops, see “Clean the Back Side of the Kiln Sitter,” next
page.
The Limit Timer Clock Does Not Operate.
Probable Causes:
■
One of the wires that con-
nects the clock motor to
the power has burned out.
■
The timer motor is burned
out.
The Kiln Sitter
Plunger (Button)
Won't Stay Pressed In
Probable Causes:
■
The Limit Timer is set to
0.
■
Something is obstructing
the locking slide.
■
The locking slide is rusted
or dirty.
■
The spring for the locking
slide is broken.
A wire may be in the way of the Kiln Sitter plunger
mechanism, preventing it from locking in the on position.
Sometimes heat causes a wire to move inside the switch
box.
Something may have fallen into the switch box and is
interfering with the plunger: a matchstick, a piece of
dried clay, a lost screw. If anything lodges where the con-
tact blocks come together, the plunger will not stay locked
on.
The locking catch is rusted or has material stuck to it.
To free the catch, try rotating the Limit Timer knob past
20 hours while pressing the Kiln Sitter plunger.
The Kiln Sitter Plunger Overheats
If the Kiln Sitter overheats, the white plastic plunger
can get so hot that it melts. Ways to prevent this:
Make sure the high temperature washer on the
porcelain tube is pressed against the firebrick kiln
wall. A spring wire retainer keeps the washer in
place. This helps prevent heat from escaping the
kiln.
Check the wires that are connected to the Kiln Sit-
ter contact block. If they are loose or corroded,
they will cause the block to overheat. This, in turn,
overheats the plunger. Heating and cooling of the
kiln can loosen the screws over time.
Has anyone ever replaced the wires that are at-
tached to the Kiln Sitter contact block? Another
reason for overheating is that the wires are too
light a gauge.
Circulate air with a fan if the firing room tempera-
ture rises past 110 degrees F. (Measure room
temperature about 3 feet from the kiln.)
The Kiln Sitter Gives Inconsistent Firing
Results
Probable Causes:
■
The actuating rod is bent.
■
The actuating rod is cor-
roded.
■
The cone supports are
warped or corroded.
The actuating rod in the
Kiln Sitter rests on top of the
cone. As the cone bends, the
rod moves downward and re-
leases a trigger that shuts off
the kiln.
As the rod corrodes, it no longer moves freely inside
the porcelain tube. The rod's pivot point causes sluggish
movement of the rod. If your Kiln Sitter is giving incon-
sistent results, this is one of the possible causes. When
you raise the rod from inside the kiln and let go, the rod
should drop freely.
The tip of the rod corrodes as it ages. That is natural.
However, if the corrosion extends all the way up to the
pivot point inside the porcelain tube, your kiln is most
likely subjected to too much moisture.
The solution to excessive moisture inside the kiln is to
dry the ware longer before firing. You could also leave the
kiln on low for a longer period at the beginning of the fir-
ing. It is better, though, to dry the ware thoroughly before
placing it inside the kiln.
Leave the top peephole plug out. This allows moisture
to exit the kiln through the peephole instead of through
the Kiln Sitter tube. But if you use the Orton down-draft
Vent Master, keep all peephole plugs inserted throughout
the firing. Leave the Vent Master on during both firing
17
Slide out the cone supports to
examine.
