Glow-worm Ultracom 18sxi Installation And Servicing page 51

State list - Accessed through Diagnostic Codes - Level 1, Installer Access d.99
Central heating mode (Priority 3)
S.00 no heating required
S.01 fan pre-run
S.02 pump pre-run
S.03 ignition
S.04 burner on
S.05 pump / fan overrun
S.06 fan overrun
S.07 pump overrun
S.08 Anti cycling period
Domestic hot water mode (Priority 2)
S.10 domestic hot water demand
S.11 fan pre-run
S.13 ignition
S.14 burner on
S.15 pump / fan overrun
S.16 fan overrun
S.17 pump overrun
Cycling / preheat mode (Priority 1)
S.20 domestic hot water cycling mode active
S.21 fan pre-run
S.22 Pump pre run
S.23 ignition
S.24 burner on
S.25 pump / fan overrun
S.26 fan overrun
S.27 pump overrun
S.28 Anticycling period
Special cases of status messages
S.30 No Heating demand from external controls 230V
S.31 summer mode
S.32 Antifreeze active – fan speed variation too high
– waiting during blocking function
S.34 frost protection active (Priority 4)
S.36 No Heating demand from external controls 24V
S.42 Accesory Module is blocking burner operation
S.53 waiting time: temperature difference flow
- return sensor too high (Check thermistor fit)
S.54 waiting time: no water in system, temperature
(gradient error) rise flow / return sensor too high
S.76 Waiting period – pressure sensor
S.96 Return-Sensor check is running, demand
(DHW or heating) is blocked
S.97 Water pressure sensor check is running,
demand (DHW or heating) is blocked
S.98 Flow / Return - sensor check is running, demand
(DHW or heating) is blocked
14 Fault Finding
STATE LISTS
Check wiring in external controller.
Check wiring at Installer Interface.
Check CH setpoint / Check external controls
Check fan connection.
Temperature below 8
connection if this is not true.
Check wiring in external controller.
Check wiring at Installer Interface.
Check accessory module.
Check flow & return thermistor connections to pipes.
Check harness connection to thermistor.
Check harness wires are not trapped between any
internal components.
Check flow & return thermistor connections to pipes.
Check harness connection to thermistor.
Check harness wires are not trapped between any
internal components.
Check system pressure - default display.
Check return thermistor connection to pipe.
Check harness connection to thermistor.
Check connection to pressure sensor.
Check pump has not seized.
Check flow & return thermistor connections to pipes.
Check harness connection to thermistor.
Check harness wires are not trapped between any
internal components.
Possible Causes
C - check thermistor
O
Diagram 14.8
51