MHS Boilers STRATA 3 220, Instructions For Installation, Servicing & Operation

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36
STRATA3
9.0 fault
diagnosis
9.1 fault list
Possible faults are entered in the following tables. The right column contains the corresponding line
numbers of the error correction list – see section 9.2. The error correction list contains possible causes
as well as information about the elimination of the fault.
Fault Indication on the Display Type of fault
Error correction list line
number – Section 9.2
(no text) Strata 3 is turned on, ON/OFF switch does not light up, 14, 29, 31
no indication in the display.
(no text) ON/OFF switch lights up, however, no indication in the display. 14, 29, 31
FAULT RU Strata 3 does not receive any PWM signal 1, 2, 4, 33, 44
from the room unit or KKM2
FAULT OS Interruption of the connection to the outside temperature sensor 1, 3, 33
IGNIT FAULT No flame after 4 ignition attempts 12, 13, 15, 16, 17, 30, 31
FLAME OUT Flame goes out 4 times in sequence in operation 13, 15, 17, 23, 27
STB WATER STB water limit exceeded* 5, 6, 7, 21, 25, 26, 31
STB EXHAUST GAS STB exhaust gas limit exceeded* 6, 7, 21, 25, 28
FAN HIGH Controller identifies fan speed too high 9, 11, 29, 31, 33
FAN LOW Fan speed too low 9, 10, 11, 18, 29, 31, 33, 44
FAN OP Fan operation is identified when fan should be off 17, 30
FLAME W/O OP Flame identified when burner should be off 17, 30
SX INTERRUPT Connection to sensor x interrupted (S1: flow temperature sensor, 3, 33
S4: Return temperature sensor, S7: Mixer circuit sensor
GAS VALVE Connection to the gas multi purpose valve interrupted 16, 21, 29, 31, 33
EEPROM Fault during the checking of the EEPROM in the controller 29, 35
FAULT SOFT Software error in the controller 29, 35
RESET BUTTON Fault during the checking of the ‘reset’ button 29, 34, 35
LIMIT F/R Boiler temperature too high 5, 6, 7
SERVICE Maintenance interval expired ‘45
A3 Connection to the gas multi purpose valve interrupted 16, 21, 29, 31, 33, 35
A6 Fault during the checking of the ‘reset’ button 29, 34, 35
A7 Fault during the checking of the EEPROM in the controller 29, 35
A9 Software error in the controller 29, 35
A0, A1, A2, A4 Fault in the controller 29, 35
CO content too high 15, 27
CO
2
content too high 15, 23
CO
2
content too low 15, 27
Yellow flames ‘23
Hot water temperature too low 3, 22, 39
Output too low ’22, 15
*STB = Limit Thermostat
The following faults are visual problems and the right column contains possible error corrections as above, to eliminate these faults.