18
EN2R--9023 9705R0--NE
TROUBLESHOOTING
CAUTION
1.
Use utmost care while troubleshooting the
A4021A, line voltage is present on some of the
terminals when power is on.
2.
Line voltage is present on the terminals when the
cover is removed. Make sure that the main power
supply is switched off before removing the cover.
3.
The A4021A contains no serviceable parts. Any
attempt or replacement of parts ( except from
internal fuse) will affect the safety of this
deviceand is therefor not allowed.
General
If you encounter a error or fail on V1 or V2, refer to the
instruction sheet of the valve.
If you encounter other problems in the system, refer to the
Troubleshooting section in the instruction sheet for the
appropriate flame safeguard control.
Upon completion of troubleshooting, be sure to perform the
Checkout procedures previously specified for the A4021A.
NOTE:
Instructions for replacing the cover and fuse are
given in the Service section.
Before making a replacement, make sure you have the
correct part (check its part number and voltage rating)
Table 5. Troubleshooting A4021A Series valve proving System
States
ALARM
V2
PWR
RUN
V1
OK
Alarm mode
Cause
Action
10
Error V2
V2 is damaged or V2 is
wrong/not connected
Check connections V2 and
if necessary replace V2
11
Failing/leaking V1
Allowed leak--rate (V1)
higher than 0.1% of the
maximum flow--rate
Check the gas pressure
switch (GPS) and if
needed replace V1
12
Error V1
V1 is damaged or V1 is
wrong/not connected
Check connections V1 and
if necessary replace V1
13
Failing/leaking V2
Allowed leak--rate (V2)
higher than 0.1% of the
maximum flow--rate
Check gas pressure switch
(GPS) and if needed
replace V2
14
Error heat demand
Heat demand read--back
error .
Check if pin 12 on A4021A
is connected
15
Error self--test
Internal
Hardware/Software error
Reset main supply, reset
A4021A; if error still
occurs: replace A4021A
= blinking LED
= LED is off
= LED on