5.7
Fuse Replacement
Fuses are marked on the circuit diagram (section 7) with type codes, e.g. F1, F2. A list of the
correct fuses is given in section8 page 23.
If a fuse has failed, it is advisable for an electrician to check the internal circuits.
Replace any failed fuses with the correct type. For safety reasons do not fit larger capacity fuses.
The fuses are near the cable entry point, and access is by removal of the back panel of the base or
control box.
6
FAULT ANALYSIS
A. Furnace Does Not Heat Up
1.
The HEAT light
is ON
2.
The HEAT light
is OFF
B. Furnace
Overheats
1.
The HEAT light
goes OFF with
the instrument
switch
2.
The HEAT light
does not go off
with the
instrument
switch
The heating
element has failed
The controller
shows a very high
temperature or a
code such as S.br
The controller
shows a low
temperature
There are no lights
glowing on the
controller
The controller shows a
very high temperature
The controller shows a
low temperature
The SSR has failed
"ON"
MF65-1.01
Check also that the SSR is working
correctly
The thermocouple has broken or has a
wiring fault
The heater switch may be faulty or need
adjustment
The contactor (if fitted) may be faulty
The SSR could be failing to switch on due
to internal failure, faulty logic wiring from
the controller, or faulty controller
Check the supply fuses and any fuses in the
furnace control compartment
The controller may be faulty or not
receiving a supply due to a faulty switch or
a wiring fault
The controller is faulty
The thermocouple may have been
shorted out or may have been moved
out of the heating chamber
The thermocouple may be mounted the
wrong way round
The controller may be faulty
Check for in correct wiring or other
fault which could have overloaded the
SSR
E range
21