Hsotram HK2, Manual

Page: 10 / 36

MANUAL
HK2 – HK4 25-08-2014
Page
10
The optimal adjustment will bring the boiler temperature just below the setting of the boiler
temperature set point as the fan stops; having the setting too low will bring the fan to stop
when the combustion is still active; this is an unwanted mode and will lead to soot and a
dirty boiler.
NOTICE: The temperature safety valve (the valve connected to the cooling coil) is starting to
open at about 95°C. Thus, it must be taken care not to set the boiler thermostat
to more than 87°C in order to avoid an untimely shutting down of the security.
1.3.8 Safety thermostat (STB) – situated on front left of controller
The thermostat switches off at 100°C and stops the electric supply of the suction fan. If this
happens, it is advisable to:
- Wait for the boiler to cool down to 75 °C.
- Unscrew the cap of the thermostat (situated on the front left to the controller), push the
little button, screw on the cap
- Use again the boiler as normal.
If this happens again, it is advisable to check the following points by your heating installer:
- Check the function of the safety thermostat.
- Check that the use of the boiler has been correct
-
Check that the boilers hydraulic system is correct (recycling system in a good state...)
- Check the function of the temperature safety valve
-
Check the function of the boiler temperature sensor.
- Check that the chimney draught is not too strong (draught stabilizer is in a good state and
well adjusted).
- Check if there is some power supply’s cuttings (main electrical supply)
1.3.9 Ash door locking
The screw provided for this purpose shall be mounted as the boiler are in use (combustion is
going on). Remove the screw only if the boiler is cold (no combustion).