Honeywell A4021 Series Product Handbook page 17

STANDBY
Modes
Timings (sec.)
*= depends on OS #
States
0 1
Line voltage
Heat demand
Pressure
(between V1 and V2
Valve 1
Valve 2
Operate burner
Alarm output
Power
Run OK
Alarm
Valve 1
Valve 2
START OPEN
STANDBY
SELF
TEST
WARNING
No standard valve proving after lock--out of the ignition controller
TEST MODE
25 *
5*
3*
5*
3*
2 3 4 5 6
TEST TEST OPEN TEST
V2 GPS
GPS
V1 V1
LOW
HIGH
RUN MODE
25 *
7 8 9
ERROR
TEST
WAIT
OPERATE
FOR BURNER
V2
START--UP (valves operated by
ignition controller)
= LED is off
ALARM MODE
10 13
11 12 14 15
FAILING/
FAILING/
ERROR ERROR ERROR
V2 LEAKING
LEAKING V1
HEAT SELF--
DEMAND TEST
V1 V2
= blinking LED = LED on