A
IR
T
OP
5000
3
F
UNCTIONAL
D
ESCRIPTION
3-3
3.1.5
Switch-Off upon Malfunction
The control unit recognizes malfunctions of individual air heater components and malfunctions in the start sequence and
in normal operation.
The air heater is deactivated and enters the error lockout mode under the following conditions:
• flame sensor resistance out of tolerance
• temperature sensor resistance out of tolerance
• glow pin/glow pin trigger defective
• fan speed too low, short circuit or open circuit
• error in metering pump electrical circuit or of overheat protection (in start phase only)
• low voltage below 10 Volt and in excess of 20 seconds for 12 Volt heaters
• low voltage below 20 Volt and in excess of 20 seconds for 24 Volt heaters
• control unit defective
In case of overheating there will be no fuel supply. A run-down like after manual switch-off will be performed. After run-
down the control unit is in the error lockout mode. Overheating is indicated by the operation indicator flashing.
For error unlock, the air heater has to be switched off momentarily (at least 2 seconds) and to be switched on again.
For more information concerning malfunction and flash codes, see section 6.2 Troubleshooting.
Heater “ON” indicator
Day of the week
Time display
Memory
location
Time
Program
selection
Instant
heating
Reverse
Forward
Temperature
selection
3.2
7-Day Digital Timer Model 1531 with 3 Time-Settings and Temperature Selector
Fig. 3-2:
7-Day Digital Timer Model 1531 with Temperature Selection for Air Top 2000/3500/5000 Air Heaters Only.