Atmos Multi Mk2, Manual, Page: 12 / 19

2.3 Malfunction messages
A malfunction is an error which is so serious that the appliance is locked. A malfunction message is identified by a
locked control unit accompanied by a flashing number or letter on the diagnostic display. The appliance can only be
unlocked by pressing the reset button.
Code
Diagnostic
display
Central heating
water display
Message
2 Fan defective (5Hz deviation per minute)
3 Incorrect ionisation (flame) signal
3. No ionisation (flame) signal during start-up procedure
4 Ionisation signal absent during heat supply (diagnostic code 1-4)
4. Ionisation signal remains present too long after heat supply
6. Gas valve control defective
7 Insufficient flow of central heating water during hot water heating
7.
Insufficient flow of central heating water during radiator heating
8 Maximum thermostat cuts out and central heating water pressure was lower
than 0.5 bar
9 Maximum thermostat cuts out and central heating water sensor was higher
than 80
o
C
9. Safety internal malfunction in control unit
Letter Internal malfunction in control unit
(Dark display) Appliance receiving no voltage
3. CAUSES OF MESSAGES
3.1 Warning messages
A warning message is identified by a letter that appears on the diagnostic display every five seconds for a period of one
second instead of the status message. The appliance continues to operate, but the function to which the message applies
will be switched off of ignored. Once the cause of the warning message has been solved, the appliance will start up
again automatically so resetting is not necessary. The possible causes are described below in order of probability. Also
look for the malfunction in this order.
Diagnostic display code Central heating water display code
Status
message
(Number)
Warning
every 5
seconds
Diagnosis Message Cause
H H
•
Central heating temperature >118
o
C
•
Connector K4 loose or improperly
connected
•
Temperature sensor wiring interrupted
•
Sensor defective
•
Control unit
b
Hot water tank temperature <-10
o
C or
>118
o
C. In sub-program sensor values
the message HH (>118
o
C) or LL (<-
10
o
C) appears on the central heating
water display.
L L
•
Control heating temperature <-10
o
C
•
Short circuit in temperature sensor
wiring
•
Sensor defective
•
Control unit
ATMOS MULTI Mk2 version 2004 Appendix Page 12