Caf Digital Imaging
page 28
MF36
7.0
F
AULT
A
NALYSIS
.
A general fault analysis chart can be seen below; see section 4.0: Operating Instructions, for
more detailed fault analysis of the control system.
A.
Furnace Does Not Heat Up
1.
The
HEAT
light
is
ON
à
An ohm meter applied
to the element circuit
shows an open circuit
à
A heating element has failed
2.
The
HEAT
light
is
OFF
The controller shows
a
very high temperature
or a code such as S.br
à
The thermocouple has broken or has
a wiring fault
There are no
lights glowing
on the
controller
à
The
SUPPLY
light is
ON
à
The controller may be
faulty or not receiving a
supply due to a faulty
switch or a wiring fault
à
The
SUPPLY
light is
OFF
à
Check the supply fuses
and any fuses in the
furnace control
compartment
B.
Furnace Overheats
1.
The
HEAT
light goes
OFF
with the
instrument switch
à
The controller shows a
very high
temperature
à
The controller is faulty
à
The controller shows a
low
temperature
à
The thermocouple may have been
shorted out or may have been moved
out of the heating chamber
à
The thermocouple may be mounted the
wrong way round
à
The controller may be faulty