5
(See Fig. 1.)
(a) Switch on the electrical mains supply to the boiler.
(b) Ensure that any external controls connected to the boiler, such
as a room thermostat, are on a high setting.
(c) If a programmer is fitted set it to the correct time of day and
position the selectors to ON.
(d) Ensure the switch on the Outdoor control box is in the ‘run’
position.
(e) Turn the thermostat control knob to the desired position
(see Fig. 2: temperature control).
(f) Your boiler will now commence a start sequence, in which a
pre-ignition period of approximately 15 seconds is followed
by a supply of atomised oil being introduced into the
combustion chamber. Ignition then occurs, followed by a post-
ignition period of approximately 20 seconds.
(g) Your boiler is now in a steady run condition and will remain so
until the water temperature reaches the temperature set on the
control thermostat. At this point the burner will stop and the
boiler will shut down. The sequence will continue until the
boiler is programmed - either manually or by an automatic
programmer - for a period of shutdown.
Fig. 1. Control Facia
HOW TO START YOUR
BOILER
Overheat
Thermostat
Reset Button
Switch
TEMP
Isolate
mains
supply
before
removing
Burner
or any
electrical
cover.
Bosch Thermotechnik
Temperature
Control Knob
Serial Number
Label
Side view of
switch in
‘RUN MODE’
RUN
SERVICE
Frost Thermostat
Outdoor Control Box
