2
【Safety Devices】
3
【Error Code】
Display
Safety device
Explanation
A1
Flame detection
When misfire occurs or flame goes out during the operation, the heater shuts
down automatically.
A2
Low fuel
No fuel in the fuel tank.
A3
Overheat
When overheating is detected, the heater shuts down automatically.
A4
Tip-over
When the heater receives a large vibration or shock, it shuts down
automatically.
A5
Abnormal fan speed
When an abnormality of the combustion fan is detected during combustion,
the heater shuts down automatically.
A6
Low voltage stop
When the supply voltage is about 70V or less, the heater shuts down
automatically.
A7
3 consecutive misfire
When there are 3 consecutive misfire, the operation is prohibited
automatically.
A8
Circuitboard communication abnomality
When communication between the control board and the operation board
fails, the operation is prohibited automatically.
HV
High voltage
When the heater is connected to an abnormal high voltage, the operation is
prohibited automatically.
LV
Low voltage detection
When the power supply volatage drops below appoximately 90volts during
operation, 「LV 」is displayed and the operation is continued.
※Refer to「7.Troubleshooting (P.6)」for countermeasure.
Safety Devices
Detecting condition
Working condition after detecting
Flame detection（Misfire）
When the heater cannot detect a ignition during operation.
The error code「A1」is displayed and the fan cools down the heater for
about 5 minutes ( hereafter refferd to as Post-purge).
When the heater detects a out of fuel at the beginning
of operation.
The error code「A2」is displayed .
When it pasted 60 minutes after the heater detects
a out of fuel.
The error code「A2」is displayed and Post-purge sequence runs for 5
minutes.
Overheat protection
When the heater overheats.
The error code「A3」is displayed and if the heater is operating , Post-
purge sequence will run for 5 minutes.
Tip-over
When the heater detects a vibration or an impacts.
The error code「A4」is displayed and if the heater is operating, Post-purge
sequence will run for 5 minutes.
Abnormal fan speed
When the heater detects an abnormal fan speed.
The error code 「A5」is displayed and if the heater is operating, Post-
purge sequence will run for 5 minutes.
High voltage
When the heater detects a high voltage(about 145V) at
the beginning of the operation.
The error code「HV」is displayed and the operation is prohibited.
Low voltage stop
When the heater detects a low voltage(about 70V) at the
during of the operation.
The error code「A6」is displayed and if the heater is operating, Post-purge
sequence will run for 5 minutes.
3 consecutive misfire
When there are three consecutive misfire.
There error code「A7」is displayed and the heater runs for 5 minutes.After
that the operation is pohibited.
Circuitboard communication
abnomality
When a communication between the control board and the
operation board fails.
The error code 「A8」is displayed and if the heater is operating, Post-
purge sequence will run for 5 minutes.
Low voltage detection
When the heater detects low voltage (about 90V) during
the operation.
The error code「LV」is displayed and the operation is continued.
Power outage safety device
When the power supply is restored after it shuts down
during operation because of blackout or other reason.
The error code「--」is displayed and the operation is prohibited.
Low fuel
3
