U.S. Boiler Company B series 2, Installation, Operating And Service Instructions

Page: 34 / 60

34
X. TROUBLESHOOTING
A.
BEFORE TROUBLEShOOTING
The following pages contain trouble shooting tables for
use in diagnosing control problems. When using these
tables the following should be kept in mind:
1. This information is only meant to be used by a
professional heating technician as an aid in
diagnosing boiler problems.
2. Where applicable, follow all precautions outlined in
the lighting instruction on page 23 .
3. In general, these tables assume that there are no
loose or miswired electrical connections. Before
using these tables inspect all electrical connections
on the boiler to make sure that they are tight. Also,
check the wiring on the boiler against the wiring
diagram in Figures 13 and 14. Ensure that incoming
120 vac power polarity is correct and that the boiler
is properly grounded. Further, ensure that the control
power supply is 24 vAC (minimum 18 vAC to
maximum 30 vAC) and polarity is correct.
4. All controls on the Series 2 are tested at least once
in the manufacturing process and a defective control
or component is generally the least likely cause.
Before replacing a component, try to rule out all
other possible causes.
5. When checking voltage across wiring harness pins
be careful not to insert the meter probes into the
pins. doing so may damage the pin, resulting in a
loose connection when the harness is reconnected.
Press “I” key on the control to change
from one parameter to the next. Each
setting will alternate between display
code (for example
STA
) and value.
When
Err
(error) is shown:
Value Description
4 Flame current lower than threshold
6 Flame Out of Normal Sequence
18 Electronics Failure
23 Flame Sensed During Pre-purge
32 Temperature Sensor Failure
55 Damper Failed to Open
56 Damper Failed to Close
57 Flame Rod Shorted to Ground
58 AC Line Frequency
59 Line Voltage Error
60 Thermostat input higher than threshold
61 Line Voltage Unstable
63 Soft Lockout – Recycles Exceeded
64 Soft Lockout – Internal Failure
Possible
STA
(status) values:
Figure 27: Using Control Display to Troubleshoot Series 2 Boiler
Value Description
1 Standby
4 Pre-purge
6 Spark
7 Flame Proving
8 Running
10 Retry/Recycle Delay
13 Soft Lockout
14 Hard Lockout
15 Waiting for Limit to Close
16 Flame Present Out of Sequence
17 Self Test
18 Waiting for Damper to Open
19 Waiting for Damper to Close
20 Damper Failure to Open
21 Damper Failure to Close