Recommissioning The Boiler; Test Operation; Troubleshooting 8; Logical Fault Finding Procedure - Vaillant ecoTEC plus 612 Instructions For Installation And Servicing

• Ensure the boiler CH service valves are closed.
• Release the pressure from the boiler.
• Remove valve cap from expansion vessel charge point.
• Check that the internal charge pressure of the expan-
sion vessel is between 0.75 and 0.9 bar.
If the pressure is lower than this the vessel should be
repressurised using an air pump.
• Refit the valve cap.
• Repressurise boiler and heating system.
7.5

Recommissioning the boiler

• Carry out electrical safety checks.
• Turn on the electrical supply.
• Open the boiler CH service valves.
• Carry out function checks of boiler operation as previ-
ously detailed.
• Check gas rate as previously detailed.
• Check for water leaks.
• Refit case, ensuring that a good seal is obtained.
7.6

Test operation

Always perform the following checks after completing
any maintenance task:
• Commission the appliance according to the relevant
operating manual.
• Check the appliance for gas and water leaks.
• Check the air/flue gas system for leaks, check its
fastening
• Check for ignition and an even flame on the burner.
• Check that the heating system and the water heating
is working (combination boilers only).
• Fill out the Benchmark gas boiler commissioning
checklist at the rear of this guide.
Fig. 7.11 Function check
Instructions for installation and servicing ecoTEC / 839592_09
Inspection and maintenance 7
8 Troubleshooting
8.1

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 boil-
er 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 sys-
tem. (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
(combination boilers only).
8. Check that all external controls are on and calling for
heat (if no external controls are fitted, boiler termi-
nals 3 and 4 must be linked). Check that the boiler
anti–cycling economiser is not engaged.

8.1.1 Status codes

The status codes that you can see on the display pro-
vides information about the current operating condition
of the appliance. The display of the status codes can be
called as follows:
plus
Fig. 8.1 Display of status codes
• Press the "i" key.
The display shows the status code, e.g. S.4 for "Burner
mode - Heating".
The display of the status codes can be cancelled as follows:
• Press the "i" key or
• Do not press any key for about 4 minutes.
The current heating flow temperature appears in the
display again.

Troubleshooting 8

pro
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