p. 8
Output relay for Main pump, Cooling, High
limit valve or other attached device.
Incorrect connection to device (output relay has volt free contacts, see master wiring diagram for
correct connection)
Bad electrical connection between terminals and attached device.
Install mode is not activated.
Attached device may be faulty.
Boiler does not fi re
(LED lit)
Incorrect connection to device (output relay has volt free contacts, see master wiring diagram for
correct connection)
Bad electrical connection between terminals and attached device.
Install mode is not activated.
Attached device may be faulty.
Timing sequence delay is activated
FS master only - mixing valve not open above 20%
No heat demand from Room sensors.
Master is in cooling mode.
(LED not lit)
Mixing valve does not operate correctly
(When in install mode)
Incorrect connection, see master wiring diagram for correct connection.
Valve/actuator assembly is incorrect.
Actuator is faulty.
Check what happens if sensor and/or outdoor module is missing.
(Valve cycles between open and closed in
normal operating mode)
Valve may be oversized.
Supply Limit sensor may be subject to heat migration.
Upstream water temperature is excessively high.
(these problems may be corrected by changing PI settings – please refer to the main manual)