ERROR MESSAGES
If a sensor fault occurs during normal
operation or during the test routine, the word
"Err" will appear in the display screen and the
display will flash back and forth between
"Err" and one of the error codes listed below.
The display flashes between "Err" and "S 1"
Check the outdoor sensor and the wiring from the
terminal plug to the sensor.
With this error, the control will operate the boilers as if
the outdoor temperature was -8
°
F (-22
°
C)
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
OUTDOOR SENSOR — SHORT CIRCUIT
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
S
S
M
W T F
T
The display flashes between "Err" and "O 1"
Check the outdoor sensor and the wiring from the
terminal plug to the sensor.
With this error, the control will operate the boilers as if
the outdoor temperature was -8
°
F (-22
°
C)
OUTDOOR SENSOR — OPEN CIRCUIT
The display flashes between "Err" and "S 2"
Check the supply sensor and the wiring from the
terminal plug to the sensor.
With this error, the control will shut down the boilers,
close the combustion air damper but leave the pump on.
SUPPLY SENSOR — SHORT CIRCUIT
The display flashes between "Err" and "O 2"
Check the supply sensor and the wiring from the
terminal plug to the sensor.
With this error, the control will shut down the boilers,
close the combustion air damper but leave the pump on.
SUPPLY SENSOR — OPEN CIRCUIT
The display flashes between "Err" and "S 3"
Check the wiring from the terminal plug to the
10K Zone Control.
With this error, the control loses its indoor temperature
feedback and operates at the Occ or Unocc settings.
ZONE CONTROL— SHORT CIRCUIT
Step Eight
Troubleshooting
As in any troubleshooting procedure, it is important to isolate a
problem as much as possible before proceeding. The 258 can
help the user in three significant ways.
(1) — The Error Messages can pinpoint certain problems and
eliminate others.
(2) — Cycling the control through the test routine allows the
operation of the various components to be examined
individually and in a systematic way to greatly simplify
troubleshooting.
(3) — The display can show outdoor, actual supply and target
supply temperatures, and the LED system status lights
display the operation of the various system components.
A competent troubleshooter can locate system faults
without having to go any further than observation of
these important temperature and status indicators.
If a fault occurs during operating mode or during the test routine
and the control is flashing an Error Message, identify the fault
from the look-up table on the right side of this page and then
follow standard testing procedures to confirm the problem.
If you suspect a wiring fault, return to steps four and five and
carefully check all external wiring and wiring connections.
Notes:
If the Outdoor Sensor develops either a short circuit or an open
circuit, the control is programmed to calculate the outdoor
temperature at -8
°
F (-22
°
C) and control the supply temperature
accordingly.
The control is programmed to shut the boilers down before the
supply temperature can reach a maximum allowable supply
water temperature of 248
°
F (120
°
C).
If the Supply Sensor develops either a short circuit or an open
circuit, the control is programmed to shut down the boilers and
run the system pump to prevent overheating.
If a Zone Control input becomes shorted out, the Occupied or
Unoccupied setting will become active.
After any repair has been completed, press the Test button
to allow the control to cycle through the test routine. This
will allow you to confirm that correct operation has been
restored and that wiring connections are undisturbed.
Step Nine
Before you leave
Make sure wiring dividers are installed in the proper locations
between compartments having different voltages.
Install the wiring cover over the wiring chamber and secure it to
the base with the two screws provided. Place the front cover on
the control to cover the setting dials and snap it into place. Install
a lock if security is required.
Place this brochure, and all other brochures relating
to the installation, in the protective plastic bag sup-
plied with the control. Place the bag in a conspicuous
location near the control for future reference, as
programming instructions will need to be accessible
for future users.
It is important to explain the operation and maintainance of this
control and of the system to the end user and anyone else who
may be operating the system.
Error Messages
14
ERROR MESSAGES
