24
7.9
COMPONENT VALUES & CHARACTERIS-
TICS
APPLIANCE STATUS LED AND FAULT CODES
When the boiler detects a temporary fault condition, the ap-
propriate led indication is shown. If/when the fault is final, the
pump will perform a 60-second post circulation and red LED
will be illuminated. See table on page. 4.
COMPONENT
VALUE
Fan
230Vac
Pump
230Vac
Ignition transformer
230Vac
Gas valve
230Vac
Room thermostat connection
24Vdc
NTC thermistor (dry contact)
10Kohm
NTC thermistor (wet contact)
10Kohm
FUNCTION
VALUE
Standard Heating temperature
range (min – max °C)
40 - 80
75% maximum CH time
15 min
Heating OFF hysterisis (°C)
SP + 5
Heating ON hysterisis (°C)
SP – 5
Anti-cycle delay
3-min
Pump over-run
30-sec
Low output (min. %)
Min+25
CO function max temp. (°C)
90
CO re-light temp. (°C)
78
CO function time
15-min
Flow NTC max temp. (°C)
90
High limit thermostat (°C)
105
Flue NTC max temp. (°C)
125
Maximum differential (°C)
35
IGNITION CONTROL
VALUE
Ignition attempts before L/O (lockout)
5
Re-ignition attempts after loss
of flame signal
5
7.6 EXTERNAL FAULTS
Before carrying out any faultfinding or component replacement,
ensure the fault is not attributable to any aspect of the installation.
7.6.1 INSTALLATION FAULTS
Symptom
Possible cause
No led/ignition
Check wiring/check electrical
supply
No hot water
Check external controls
No heating
Check external controls
Fault
Possible cause
Red led fixed
Check gas supply, check flue
system, check polarity
7.7 ELECTRICAL CHECKS
Any electrical checks must be carried out by a suitably quali-
fied person.
7.7.1 EARTH CONTINUITY TEST
Isolate the appliance from the electrical supply, and using a
suitable multi-meter carry out a resistance test. Connect test
leads between an appliance earth point and the earth wire of
the appliance supply cable. The resistance should be less than
1 OHM. If the resistance is greater than 1 OHM check all earth
wires and connectors for continuity and integrity.
7.7.2 SHORT CIRCUIT CHECK
Isolate the appliance from the electrical supply, and using a
suitable multi-meter, carry out a short circuit test between the
Live & Neutral connections at the appliance terminal strip.
Repeat above test on the Live & Earth connections at the ap
-
pliance terminal strip.
NOTE
Should it be found that the fuse has failed but no fault is in-
dicated, a detailed continuity check will be required to trace
the fault. A visual inspection of components may also assist
in locating the fault.
7.7.3 POLARITY CHECK
With the appliance connected to the electrical supply and us-
ing a suitable multimeter, carry out the following voltage tests:
•
connect test leads between the Live & Neutral connections
at the appliance terminal strip. The meter should read ap-
proximately 230V ac. If so proceed to next stage. If not, see
7.7.4.
•
connect test leads between the Live & Earth connections
at the appliance terminal strip. The meter should read ap-
proximately 230V ac. If so proceed to next stage. If not, see
7.7.4.
•
connect test leads between the Neutral & Earth connections
at the appliance terminal strip. The meter should read ap-
proximately 0 – 15Vac. If so polarity is correct. If not, see
7.7.4.
7.7.4 REVERSED POLARITY OR SUPPLY FAULT
Repeat the above tests at the appliance isolator, if testing
reveals correct polarity and/or supply at the isolator, re-check
wiring and connections between the isolator and the appliance.
If tests on the isolator also reveal reversed polarity or a supply
fault, consult the local electricity supplier for advice.
7.7.5 RESISTANCE TO EARTH CHECK
Isolate the appliance from the electrical supply, and using a
suitable multi-meter carry out a resistance test. Connect test
leads between the Live & Earth connections at the appliance
terminal strip. If the meter reads other than infinity there is a
fault that must be isolated, carry out a detailed continuity check
to identify the location of the fault.
These series of checks must be carried out before attempting
any faultfinding procedures on the appliance. On completion
of any task that required the disconnection and re-connection
of any electrical wiring or component, these checks must be
repeated.
7.8 FAULT FINDING
Before attempting any faultfinding, the electrical checks as
detailed in 7.7 must be carried out. Isolate the appliance from
the electrical supply.
Disconnect any external controls from terminal plug (CN1 fig.
42), and insert a link-wire between the two wires at the ‘TA’
connections.
NOTE
Restore the electrical supply to the boiler and turn the selector
switch to the on position. The boiler should now function as
described in section 7. Should the boiler fail to respond, the
internal fuses and connectors should be checked to ensure
integrity and continuity.
