© 2022 Staheli West
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Faults
Fault 207: Pressure Differential Alarm
Indicates that the two steam pressure sensors are reading more than 2 psi (default setting) apart from each
other.
*Bad steam pressure sensors can damage input cards and PLC’s. They can also cause max readings for all
inputs on card 1 on the PLC.
** If the PLC or input card are replaced before a possible faulty steam pressure sensor is replaced, the
steam pressure sensor can damage the newly replaced components. (Replace components in order shown
below).
Causes
Troubleshooting
Fixes
• Faulty/disconnected steam
pressure sensor.
• Compare steam
pressure sensors
against manual
pressure gauge to
determine which sensor
is reading incorrectly.
• Replace sensor (RELEASE
BOILER PRESSURE BEFORE
REPLACING).
• Reconnect sensor.
• Temporary fix: Menu > Settings
> Boiler Pressure > Pressure
Sensor Selection > Select
the sensor that matches the
manual pressure gauge (NOT A
PERMANENT FIX).
• 1 or more pigtail valves are
open.
• Steam can be seen coming out
of the front supply water tanks.
• Close the open pigtail valves
(don’t forget the one behind the
manual psi gauge).
• Faulty input card 1 in the PLC.
• Perform “Test 13”.
• Replace faulty input card (see
“Test 13”).
• Faulty PLC.
• If after replacing the sensor and
the input card 1 there is still an
abnormal reading this indicates a
faulty PLC.
• Replace PLC.
