HAMWORTHY HEATING LTD
28
UPTON FLOOR STANDING SERIES
500001340/C
9.0 FAULT FINDING
The Upton boiler is equipped with full self
-
diagnostic fault indication, with faults being allocated a code. A lockout
will be denoted by a flashing LED on the fascia panel which will also be constantly illuminated by a block error
-
refer to
the separate Navistem manual.
The common fault codes are detailed in
the separate user instructions guide.
Fault codes not detailed in this
manual should only be investigated by an Engineer.
Should a fault code appear which cannot be reset, or a fault code repeatedly occurs,
contact Hamworthy Heating for assistance. Do not continue to operate or use the boiler
9.1 Safety Temperature Limiter (Limit Thermostat)
1. The electronic control thermostat has several safety levels built in such that a controlled shutdown should occur
before the safety temperature limiter is activated. Should these safety levels be overridden (say external pump
overrun failure after shutdown) the safety temperature limiter will trip initiating a boiler shutdown, preventing the
boiler from firing. A code on the controls display will flash indicating that the safety temperature limiter has tripped.
2. The limit thermostat (mounted on the front of the heat exchanger assembly
-
visible after removing the front
cover) will automatically reset after the boiler returns to a normal operating temperature.
3. Always carry out an investigation to ascertain the reason for overheating. The most common cause of
overheating is lack of water flow rate through the boiler
-
possibly due to external pump problem.
9.2 Ignition Controller
1. The flame is under constant supervision by the burner ignition controller. The controller monitors the flame’s
ability to rectify an AC current. If the flame diminishes for whatever reason and the rectified current drops below
the controller’s minimum detection current, the controller will de
-
energise the gas control valve within 1 second
and commence a restart. Failure to establish and detect a flame during the light
-
up sequence will result in burner
shutdown and lockout within 5 seconds, requiring a manual reset to restart the ignition sequence.
2. If the boiler continues to lockout, then an investigation must be made to ascertain the cause.
3. A false flame signal at the start and during pre
-
purge will cause the boiler module to restart its ignition
sequence at the end of the pre
-
purge period. If this occurs 3 times in succession the controls will disable
operation of the boiler module, requiring reset of the module.
9.3 Water Flow Switch
1. The water flow switch is located on the return pipe
(
see Figure 8.5.4 ) and will prevent the boiler from firing
should there be inadequate or no water flow. This is to protect the heat exchanger from damage in the absence of
water (dry firing) which will cause catastrophic failure of the heat exchanger.
2. The operation of the flow switch can be checked by closing one of the isolating valves connecting the boiler to
the system, this will generate error E164 on the HMI display.
