Fault Finding; Component Values & Characteristics - VOKERA Easi-Heat Plus 25C User Instructions

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 connec-
tions at the appliance terminal strip. The meter should read
approximately 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 (CN5 fig.
39), 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.
24
7.9 COMPONENT VALUES &
CHARACTERISTICS
COMPONENT
Fan
Pump
Valve actuator
Ignition transformer
Gas valve
Room thermostat connection
NTC thermistor (dry contact)
NTC thermistor (wet contact)
FUNCTION
Standard Heating temperature range
(min – max °C)
DHW temperature range (min – max °C)
75% maximum CH time
Heating OFF hysterisis (°C)
Heating ON hysterisis (°C)
DHW OFF hysterisis (°C)
DHW ON hysterisis (°C)
Anti-cycle delay
Pump over-run
Low output (min. output + %)
CO function max temp. (°C)
CO re-light temp. (°C)
CO function time
Flow NTC max temp. (°C)
High limit thermostat (°C)
Flue NTC max temp. (°C)
Maximum differential (°C)
IGNITION CONTROL
Ignition attempts before L/O (lockout)
Re-ignition attempts after loss of flame
signal
APPLIANCE STATUS LED AND FAULT CODES
When the boiler detects a temporary fault condition, the appro-
priate led indication is shown. If/when the fault is final, the pump
will perform a 60-second post circulation and the red LED will
be illuminated. See table on pag. 4.
VALUE
230Vac
230Vac
230Vac
230Vac
230Vac
24Vdc
10Kohm
10Kohm
VALUE
40 - 80
37 - 60
15 min
SP + 5
SP – 5
SP + 5
SP + 4
3-min
30-sec
Min+25
90
78
15-min
90
105
125
35
VALUE
5
5