6
3.
Boiler description
3.1
Boiler drum construction
The cast iron section boiler drum is the main part of boiler and it is manufactured of grey cast iron according
to EN 1561
•
central sections – quality 150 (previously
Č
SN 42 2415)
•
front and rear sections – quality 200 (previously
Č
SN 42 2420)
The pressure parts of boiler conform to the strength requirements according to EN 303-5.
The boiler drum is assembled of sections by means of pressed on boiler insertions and secured by means of
anchor bolts. The sections create the combustion and ash-pan space, the water space and convection part.
The inlet and outlet of heating water are situated in the rear part of boiler.
The rear section of boiler in its upper part has a smoke extension piece and heating water flange, in the lower
part there is the return water flange with a sleeve piece for inlet and outlet cocks. The cleaning door and ash
door with mounted burner are affixed to the front boiler section.
The whole boiler drum is insulated by means of a health harmless mineral insulation which reduces the
losses caused by the heat transfer into ambient. The steel shell colour is treated by means of high-quality
komaxit spray.
3.2
Control, regulation and safety elements
Elements for control, regulation and safety placed in the control cabinet
Thermomanometer serves for measuring the temperature and pressure of water in the heating system and
is located in the upper part of the boiler shell. The check valve for pressure gauge connection is located in the
upper part of the rear boiler section.
Operating thermostat switches off / switches on the operation of the burner according to the set
temperature of heating water.
Signalling of safety thermostat signals the activation of the safety thermostat (overheating of the heating
system above 97 °C)
The safety thermostat is placed in the control box and serves for ensuring the heating system against
overheating. This thermostat is set by the manufacturer to a temperature of 95°C, i.e. to a higher temperature
than can be set as the desired temperature on the boiler. When you turn off the safety thermostat unblocking
must be done manually. The safety thermostat can be turned on only after the temperature has dropped
below the set value. We have to unscrew the black cap of the safety thermostat and by using a suitable
object we press the button.
In case of repeated switching of the thermostat the boiler must be shut down and the reason of repeated
overheating of the boiler must be found out.
The thermostat of the pump switches on and switches off the pump of heating water according to the set
temperature.
1.
Termomanometer
2.
Operating thermostat
3.
The switch "start of burner"
4.
Signalling of safety thermostat
5.
Fuse 10A
6.
Main switch
7.
Safety thermostat
8.
Thermostat of pump
Fig. no. 2
Control box
Elements for control, regulation and safety placed on the boiler body
The air rosette of cleaning door and the lower stifling element is not used at the boiler with an automatic
combustion of wooden pellets and must be permanently closed.
