Fault Finding; Safety Features Summary - Hamworthy Wessex 100 M100 Installation, Commissioning And Servicing Instructions

Figure 11.4.5 Diagram of Damper Mechanism
LIMIT STOPS
RETURN SPRING

12.0 FAULT FINDING

12.1 Safety Features Summary

Should the control
temperature limiter will trip thus creating an
immediate shutdown regardless of firing mode. An
overheat neon on the controls fascia will indicate
this condition has occurred. If, after pushing the
reset button, the neon on the fascia does not
extinguish and the boiler does fire up, it could be
that the boiler is still too hot, i.e. the limit thermostat
has not re-set. Allow the boiler to cool down. An
investigation should be carried out to ascertain the
reason for the overheating.
would be too low a water flow rate through the
boiler.
HAMWORTHY HEATING LTD
thermostat(s) fail,
An obvious reason
The flame is under constant supervision by the
burner sequence controller. This is accomplished
by measuring the flame's ability to rectify an AC
current. If the flame diminishes for whatever reason
the and the rectified current drops below the controllers
minimum
controller will induce a lockout within 1 second,
which will require a manual re-set (situated on the
controls fascia) to re-start the control sequence.
Failure to establish and detect a flame during the
light up sequence, results in burner shutdown and
lockout within 5 seconds. If the boiler continues to
lockout, then an investigation must be made to
ascertain the cause. See Figure 12.2 (p21/22) for
possible corrective scenarios. False flame signals at
the start and during pre-purge will cause the boiler
to lockout.
19
WESSEX 100 M
SOLENOID
ACTUATOR SPRING
DAMPER BLADE
detection current
AIR SENSING
(0.7µA DC), the
500001080/F