Bonus Plus Instructions Tarm Biomass 1-800-782-9927 Version 11/14 Page 28
When might an adjustment of these aquastats become necessary?
It may be desirable to lower the boiler aquastat setting to 80 °C (176 °F) if you experience
tripping of the thermal fuse or if the pressure relief valve has let go.
It may be desirable to adjust the setting of the flue gas thermostat if the amount of embers
left at the end of a burn cycle (after the induction fan has shut off) is not enough to easily
ignite the next fire. Poor fuel quality and excessive chimney draft can also contribute to this
problem. Some suggestions for changes you may want to make:
If, after the induction fan stops, there are no embers remaining in the firebox, set the flue
gas thermostat to 110 °C (230 °F) – 120 °C. (248 °F).
If there are too many embers left in the firebox, covering the entire bottom of the firebox, try
setting the flue gas thermostat to 85 °C (182 °F) or 80 °C (176 °F).
Safety thermostat (D)
This thermostat cuts the electricity supply to the combustion fan if the boiler temperature
exceeds 100 °C (212 °F). If this happens, it is advised that you:
1) Wait for the boiler to cool down to 75 °C (167 °F) or lower.
2) Unscrew the cap (D), push the little button under the cap which resets the safety thermo-
stat, screw the cap back on
3) Restart the boiler and use normally
.
If this happens again, please have a service technician check the following:
Check that the boiler has been used correctly
Check that the boiler supply and distribution system are installed and operating correctly
Check the function of the boiler temperature thermostat.
Check the function of the safety thermostat.
Check that the chimney draught is not too strong.
Closing the ash door
The ash door latch must be firmly secured against the screw, highlighted in orange below, when the
boiler is in use to avoid the door opening inadvertently while the boiler is running.
Door Locked
Door Unlocked
A 4 MM Hex wrench is necessary
to fit/unfit the screw (screw high-
lighted in orange at left)
Fig. 4.5
Fig. 4.6
Boiler Operation, Maintenance, and Service > Control Panel Orientation