36
6.1.2 Safety thermostat
The safety thermostat is mounted on the left-hand side part of basement shell and it serves for boiler
shutdown in case the safety temperature has been exceeded. The safety thermostat must be set to 100 °C
temperature i.e. to the temperature higher than the set maximum boiler temperature (90
o
C). After the safety
thermostat switch-off the safety thermostat signal lamp will light up. The fuel feeder and ventilator will stop.
The safety thermostat de-blocking must be done manually – after the cover dismantling and then pressing
the trap.
In case of safety thermostat repeated switch-offs it is necessary to put the boiler out of service and find the
reason of boiler repeated overheating. After the safety thermostat switch-off the primary pump (or HC pump)
is still working.
6.1.3 Temperature sensor on the fuel feeder
If the temperature set in P26 parameter appears on the temperature sensor the fuel feed will be accelerated
in order to move the burning fuel to the burner. Once the temperature has dropped below the set value the
boiler will come back into the original regime. This security only functions in case the boiler is supplied with
electricity. If the feeder temperature hasn’t dropped within 7 minutes (preset value) the feeder will be shut
down.
6.1.4 Emergency fire-extinguishing system
In case of fuel fire penetration into the feeder (95
o
C temperature reached on the feeder) the BVTS
(TS 130, STS 20) valve opens the water inlet into the hopper in order to extinguish the burning fuel;
once the temperature on sensor has dropped by 6°C the water inlet will be closed.
6.1.5 Forced withdrawal of superfluous heat
6.1.5.1 Forced withdrawal of superfluous boiler heat
In case the boiler temperature has exceeded 90 °C so called forced withdrawal of the superfluous heat into
the heating circuit will start. The fan and feeder are not active. In case the temperature is lower than the
current desired boiler temperature the boiler comes back into actual automatic regime (in case the boiler
temperature has reached 100 °C and the safety thermostat has been blocked the thermostat must be
manually de-blocked).
Mixing heating circuit
Forced withdrawal of the superfluous heat is activated in case the outlet boiler temperature 90
o
C has been
exceeded. The outlet boiler temperature by means of three-way mixing valve will be reduced to the maximum
heating circuit temperature (80
o
C – parameter P 77).
6.1.5.2 Forced withdrawal of superfluous water heater heat
If the temperature in water heater has exceeded 80
o
C the forced withdrawal of the superfluous heat into the
heating circuit will start (only in case of pump heating circuit).
6.2
SAPHIR regulator parameters
In he next tables there are listed parameters that can be changed by means of QAA 88 device. The way of
displaying and changing the parameters is described in chap. 6.3.1.
Note:
HW – warm water
HC – heating circuit
