16 Combustion analysis
Fault Finding 17
Again in screen ‘8’, Set the appliance fan speed/burner
to minimum by pressing the ‘-‘ key until ‘1’ (burner to
Pmin) is shown on the right hand side of the screen.
Press the ‘mode’ button again.
Fig. 16.5
Check the CO
2
value, which should be 8.8 %
±
0.2 %. If
adjustment proves necessary then proceed as follows.
Adjustment of the CO
2
at minimum rate is very coarse,
so carefully adjust the CO
2
with the (‘B’) offset adjust-
ment using a 2mm allen key to 8.8 %, (rotate clockwise
to increase).
After checking the combustion, press and hold the
‘mode’ button for 10 seconds to return to the normal
mode, showing the current flow temperature. Replace
the cap on the sampling point and refit the outer front
case.
Note!
Depending on the time to take the readings, the
display may default back to the normal mode, it
may be necessary to repeat steps 3,4 and 5 to
adjust the appliance fan speed/burner.
17 Fault Finding
Logical fault finding procedure
These checks must be carried out before attempting to
use the fault finding guide.
1. Carry out electrical safety checks (see section ‘prelimi-
nary electrical checks’ 13.1).
2.Check that the external electricity supply to the boiler
is on, and a supply of 230V is present at the boiler
terminal strip.
3. Check that the gas supply to the boiler is on, that it
has been correctly purged and that an inlet pressure
of 20mbar is available at the gas valve (see section
‘gas supply’ 13.3).
4.Check that the main on/off control is set to the ‘on’
position.
5.Set the central heating temperature to maximum.
6.Check that all external controls are on and calling for
heat.
7. Check that all manual circuit controls ie. bypass, radia-
tor valves are correctly adjusted.
17.1 Status Mode
A series of status mode screens are available for current
boiler operating information.
To display the status mode, proceed as follows:
• With the interface in ‘normal’ mode, press and hold
the ‘mode’ button (
) for 10 seconds until a flashing
‘0’ appears (fig. 17.1).
• Press the ‘-‘ key and scroll through until ‘96’ (installer
mode) is shown on the screen, then press the ‘mode’
button again.
• A series of screens are then available for service func-
tions. An example is shown in fig. 17.2 (screen 23 ‘pro-
duct code’ for the ecoMAX pro 18E).
Fig. 17.1
Fig. 17.2
Instructions for Use, Installation and Servicing ecoMAX pro
28
18E
28E *
Output
Min
Max
Min
Max
Burner % CO
2
Case on (
±
0.2)
9.0
9.0
9.0
9.0
Case off (
±
0.2)
8.8
8.8
8.8
8.8
Approx. gas rate
(after 10 mins
0.53
2.00
0.56
3.02
from cold) m
3
/h
* ecoMAX pro 28E only - for LPG see page 23