63
ecoTEC plus 937 installation and maintenance manual
• Isolate the unit from the mains as described in
Section 9.1.
• Close the gas isolation valve in the gas supply pipe.
• Comply with the assembly and installation manuals
provided with the spare parts.
• Remove the screw on the top cover of the shift load
storage tank and remove the cover.
• Pull the electronics (
1
) out of the location slot.
• Pull off the plug connector from the wiring harness.
• Fit the new electronics in reverse order.
• Start up the appliance.
Check the correct setting of the unit variants (DSN) as
follows:
• Enter the 2nd diagnostic level of the combi boiler .
• Set the equipment-specific DSN value (parameter
"
d.93
“) in accordance with Table 10.1.
Appliance type
DSN
ecoTEC plus 937
8
Table 9.1 DSN Setting Values
• Exit the diagnostic mode.
The combi boiler ecoTEC plus 937 is ready for operation.
9.10
Replacing the electronics and the display on
the combination boiler
d
Danger!
Before replacing components ensure that the
safety instructions from Section 9.1 are
observed.
• Comply with the assembly and installation manuals
provided with the spare parts.
Replacing the display or the electronics
If you are only replacing one of the two components the
parameter settings take place automatically. When
switching the unit on the new component automatically
takes the pre-set parameters from the components
which have not been changed.
Replacing the display or the electronics
When replacing both components, after being turned on,
the appliance goes to fault and displays the error
message
F.70
.
• In the second diagnostic level, under the diagnostic
point "d.
93
" enter the number of appliance variant
according to Table 9.1 (see Chapter 9.9).
The electronics is now set to the appliance type and the
parameters of all adjustable diagnostic points
correspond to the factory settings.
9.11
Checking and setting the CO
2
content, if
required (air ratio adjustment)
h
Note!
Checking/adjusting this value is only required
under the following circumstances: Replacing
the gas valve, converting from or to natural
gas/propane during an annual service (if a flue
gas analyser is available) or under suspicion of
faulty combustion!
• Remove the front cover.
• Press the "
-
" and "
+
“ buttons simultaneously.
The "full load mode" is activated.
• Wait at least 5 minutes until the appliance reaches its
operating temperature.
2
1
Fig. 9.11 Measurement of the CO
2
content; Preparation air
figure setting
• Measure the CO
2
content at the flue gas analysis
point (
1
) of the flue adapter.
• If required, remove the screw and swing the air inlet
pipe downwards through 90° (do not remove!).
• If necessary, set the corresponding flue gas value
(value with removed appliance front, see Table 9.2) by
turning the screw (
2
).
-> Turn to the left: Higher CO
2
content
-> Turn to the right: Lower CO
2
content
Replacing components 9
