10 Fault finding
10 Fault finding
10.1 Introduction
The aquaPLUS boilers have an inbuilt advanced
multifunction diagnostic display to assist with fault
finding in the unlikely event of a boiler malfunction.
The display features the following four modes:
Normal Mode
Under normal conditions the boiler display will show the
boiler flow temperature, this indicates that the boiler is
operating correctly after an internal self check.
Status Mode
The status display is helpful in diagnosing faults where a
fault code is not displayed.
Diagnostic Mode
In order to assist with the pinpointing of a particular
fault it is possible to use the boiler display in a
diagnostic mode to interrogate the boiler about the
status of certain components.
Fault Mode
Should a fault develop in the boiler the display will show
a fault code indicating what the problem may be.
Display key:
1 Fan speed malfunction
2 Heating demand
3 Hot-water demand
4
Power store
on (Comfort mode)
5 Pump on
6Gas valve on
7 Actual Heating-system flow temperature (e.g. 50 °C)
or
Displaying of a status/error code
8 Correct burner operation (normal flame) or
lock out (crossed-out flame)
Instructions for installation and servicing aquaPLUS VUI 362-7
36
Fig. 10.1: Display indications
10.2 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
‘Preliminary Electrical Checks’).
2.Check that the external electricity supply to the boiler
is on, and a supply of 230 V~ is present between
boiler terminals ‘L’ and ‘N’.
3. Check that the gas supply to the boiler is on, that it
has been correctly purged and that an inlet pressure
of 20 mbar is available at the gas valve. (See Section
‘Gas Supply’).
4.Ensure the heating system is full of water and
charged to between 1 and 1.5 bar. If not, refill and vent
the system. (See Section ‘Filling the heating system’).
Ensure boiler flow and return service valves are open.
5.Check that the main on/off control is set to the ‘on’
position.
6.Set the central heating temperature to maximum.
7. Set the domestic hot water temperature to maximum.
8.Check that all external controls are on and calling for
heat (if, no external controls are fitted, boiler
terminals 3 and 4 must be linked). Check that the
boiler anti-cycling economiser is not engaged.
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