Troubleshooting - Honeywell A4021 Series Product Handbook

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.
States
PWR RUN ALARM
OK
10
11
12
13
14
15
= LED is off
Table 5. Troubleshooting A4021A Series valve proving System
V1 V2
Error V2
Failing/leaking V1
Error V1
Failing/leaking V2
Error heat demand
Error self--test
= blinking LED = LED on
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)
Alarm mode
V2 is damaged or V2 is
wrong/not connected
Allowed leak--rate (V1)
higher than 0.1% of the
maximum flow--rate
V1 is damaged or V1 is
wrong/not connected
Allowed leak--rate (V2)
higher than 0.1% of the
maximum flow--rate
Heat demand read--back
error .
Internal
Hardware/Software error
18
Cause
Check connections V2 and
if necessary replace V2
Check the gas pressure
switch (GPS) and if
needed replace V1
Check connections V1 and
if necessary replace V1
Check gas pressure switch
(GPS) and if needed
replace V2
Check if pin 12 on A4021A
is connected
Reset main supply, reset
A4021A; if error still
occurs: replace A4021A
EN2R--9023 9705R0--NE
Action