43
9.2.4 Service
mode
Service mode displays the boiler operation sequence and mode.
To enter the service mode:
In the temperature mode briefly press the
‘prog’
-key twice. Each subsequent press of
this key will display the numbers and letters of the relevant operating codes displayed
in sequence (
)
–
(
) with a flashing red dot.
A description of the meaning of each code is given in
Table 07.
Step
Description
0
Idle, no heat demand
1
Pre-purge / post-purge
2
Ignition
3
CH - On
4
DHW - On
5
Waiting for fan to reach high speed
6
Flow temperature more than 5°C above set point
7
Pump over run CH-mode
8
Pump over run DHW mode
9
Burner off because one of the following has been exceeded:
- Flow temperature set point
- Flow temperature rise to fast
- Difference between flow and return temperature exceeding 45°C
H
On ‘forced High’ mode*
L
On ‘forced Low’ mode*
Table 07 Description of Service mode read-out
*
See Par. 9.2.5 and 9.2.6 for access.
Note:
If no key is pressed for 1 min whilst in service mode, it automatically returns to
temperature mode.
9.2.5 ‘Forced High’ mode
In ‘forced High’ mode the appliance will operate at its maximum output for 15 minutes
(flow temperature dependant). This is the output setting for DHW operation. To enter
this mode, press the
‘prog’-
key briefly three times whilst in temperature mode. The
letter
H
then appears on the display. By pressing the
‘prog’-
key for more than 1 sec,
the ‘forced High’ mode becomes active. The letter
H
flashes twice to confirm this. To
terminate this mode prematurely press the
‘prog’-
key again for more than 1 sec..
