Rayburn 370 SFW Installation Instructions Manual - page 22
THERMOSTAT WITH MANUAL OVERRIDE
The air supply to the fire is controlled by the thermo-
stat probe inserted into the boiler and the control knob
attached to the ash door.
The automatic thermostat has 6 settings which control
the heat to which the boiler water will rise for central
heating purposes. Setting 0 will close the thermostat,,
setting 3 will give a nominal burning rate of 2
1
/
2
to 3kg
per hour of house coal. Setting 5 will give maximum
water heating and high oven temperatures.
The thermostat will close down when the water
reaches the temperature chosen by the selected set-
ting, it will close fully when the water temperature
reaches 90 - 95
o
C when set at 5 - to prevent boiling.
(See Fig. 5)
The thermostat manual override has 4 settings which
retain the air flap in a predetermined open position for
steady heat when baking and cooking. It will only
close fully when the water temperature reaches 90 -
95
o
C when set at 5 - to prevent boiling.
Fig.4
Control
Knob
Riddling
Cover
Fig.5
There is a small air bypass into the ashdoor and this
is normally sufficient when the thermostat is closed to
hold the fire at least 10 hours after banking. If the fire
is out and the fuel unburned set the control knob of
the thermostat from
1
/
2
to 1 in order to sustain
overnight burning.
OVERNIGHT BURNING
FIREDOOR SPIN VALVE
Fig.6
Heated secondary air enters the firebox through a
spin valve in the firedoor back plate while the valve is
open to assist combustion of smoke volatiles.
Close when burning anthracite. (See Fig.6)
The ashdoor spin valve allows additional air to the
firebox for marginal draught conditions. This can be
adjusted to suit your requirements. Close when set-
ting the cooker for overnight burning. (See Fig.7)
ASHDOOR SPIN VALVE
Spin Valve
Fig.7
6