Fault Finding - andrews MAXXflo EVO CWH 90/302 Installation And Maintenance Manual

5.6 FAuLT FINDING

5.6.1 OPERATION SEQuENCE
To operate this heater you must have sufficient gas volume and be of the correct gas type. Electricity supply,
220-240v 50Hz and a valid demand from the DHW system.
ALL MODELS
1. The circulation pump is turned on.
2. The gas control starts the ignition sequence following a demand for DHW.
3. The fan operates on the heat engine as a pre-purge of the heat engine airways.
4. After 15 seconds of fan operation, a spark is created at the electrode and the gas valve is opened.
5. The ignition spark and gas valve opening will last for a maximum of 10 seconds.
6. A 10 second period of flame stabilisation will occur immediately after a successful ignition.
7. The controls will check that a flame is present. If no flame is detected, stages 1 - 6 will be repeated
4 further times (within 24 hours) before a permanent lockout of that heat engine occurs.
8. On successful confirmation of a flame, the fan speed is varied by the controls to suit the demand
conditions.
9. Both heat engines together, will continue to operate until DHW demand has been met, the control
timer has turned off the demand or the controls detect a fault condition.
NB: If one heat engine is in a lockout condition , this should not affect the other heat engine's ability
to function and the heater should continue to operate as normal, using the other heat engine.
5.6.2 FAuLTS AND LOCKOuTS
If a heat engine is unable to ignite or detects a safety condition, the control of that heat engine will lockout
and will be prevented from firing again, without manual intervention. The display will show the
along the top bar of the GUI display to indicate that there is a fault.
Refer to section 6.6 at the end of this manual for a full list of fault codes
The fault will have to be cleared before that heat engine will function again. Selecting from the info pages
menu will provide the fault detail (see section 6.6 at the end of this manual for the possible fault codes).
Press the RESET button on the front of the heater and provided the condition has been corrected the heat
engine will run through the ignition sequence again and the
a short delay.
5.6.2.1 FAuLT DISPLAy EXAMPLES
The display will show a
the info pages menu . See example screen:
Info pages
CAuTION
A Lockout condition should not be repeatedly reset. If the condition persists then a qualified
repair engineer should be called.
Commissioning
if the heater has recorded a fault. More information can be obtained by selecting
Error
322: Water Pressure 3 too high
symbol will disappear from the display after
51
symbol
Fault symbol
MAXXflo EVO