VOKERA Mynute EHE Installation & Servicing Instructions Manual - page 18
16
Fig. 21A
Fig. 22
Fig. 21
6.7
AUTOMATIC AIR RELEASE VALVE (fig. 17, AAV)
Carry out component removal procedure as described in
6.4. Locate and remove the expansion pipe securing pin
and disconnect the expansion pipe from the pump assem-
bly. Locate and remove the AAV securing pin (
G
) and lift the
AAV free from the pump assembly. Replace in the reverse
order.
6.8
WATER PRESSURE SWITCH (fig. 1)
Carry out component removal procedure as described in
6.4. Disconnect the 2-wires from the water pressure switch,
taking note of their locations. Locate and remove the pin that
secures the water pressure switch to the flow pipe. Remove
the water pressure switch from the flow pipe. Replace in the
reverse order.
6.9
PRESSURE GAUGE (fig. 1)
Carry out component removal procedure as described in
6.4. Locate and remove the pressure gauge securing pin
and disconnect the pressure gauge from the pump assem-
bly. Locate the spring tabs on the pressure gauge body,
push and hold tabs in, to enable extraction of the gauge from
its location on the control panel. Replace in the reverse
order.
6.10
PRIMARY THERMISTOR (fig. 19)
Carry out component removal procedure as described in 6.4.
Unclip and remove the air chamber cover and remove the
right side air baffle. Disconnect thermistor electrical plug.
Using a 13mm spanner slacken and remove the thermistor
and sealing washer (1,2) from the main heat exchanger.
Replace in the reverse order.
6.11
HIGH LIMIT THERMOSTAT (fig. 20)
Carry out component removal procedure as described in
6.4. Unclip and remove the air chamber cover. Pull off
electrical connections from the high limit thermostat (2),
slacken and remove retaining screws (3). Replace in re-
verse order.
6.12
PRINTED CIRCUIT BOARD (fig. 21)
Carry out component removal procedure as described in
6.4. Locate and remove the screws that secure the PCB
cover, then remove cover. After carefully taking note of all
wiring connections, disconnect all wiring from the PCB,
locate and remove the PCB securing screws, remove the
PCB. Replace in the reverse order.
NOTE
Ensure that any replacement PCB has the correct jumper
tag configuration, and that the relevant gas pressures are
correctly set/adjusted (see 7.8.1).
6.13
GAS VALVE (fig. 22)
Carry out component removal procedure as described in
6.4. The gas valve must be changed as complete unit.
Disconnect the electrical plug and leads from the gas valve.
Slacken and unscrew gas valve inlet and outlet connec-
tions.
Please note
,
the sealing washers must be discarded
and replaced with new sealing washers. Locate and re-
move gas valve retaining screws on the underside of the
boiler if required. The gas valve can now be removed.
Replace in the reverse order. Check and adjust burner
pressure settings.
WARNING, A GAS SOUNDNESS
CHECK MUST BE CARRIED OUT.
6.14
INTEGRAL TIME SWITCH (if fitted)
Carry out component removal procedure as described in
6.4. Locate and remove the PCB cover and securing
screws (fig. 21/21A), locate and remove the time clock
retaining screws, remove time clock. Disconnect wiring
after carefully taking note of all electrical connections.
Replace in the reverse order.
6.15
ELECTRODE, BURNER & INJECTORS (fig. 23)
Carry out component removal procedure as described in
6.4. Unclip and remove the air chamber cover (2). Locate
and remove the 6 screws securing the front combustion
cover (3), pull the cover towards you before lifting and
disengaging. Disconnect the electrode lead from its con-
nector. Ease the electrode sealing grommet from its seat-
ing (4). Remove the retaining screw (5) for the ignition
electrode (1) and remove it.
FIG. 24:
locate and remove the four screws which secure
the burner in position (1), gently ease the burner out of its
location. Once the burner has been removed, the electrode
retaining screw can be can be removed. Locate the burner
injectors (2) and remove (if necessary). Replace in the
reverse order.
Please note,
the injector sealing washers (3) must be
replaced if the injectors have been removed, ensure all seals
are in good condition, taking care to ensure they are replaced
correctly. Replace in the reverse order.
Fig. 18
B
M
M
CLK-1
CLK-4
Fig. 19
Fig. 20