Commissioning Part I 6; Preliminary Electrical Checks; Gas Supply; Cold Water Supply - Vaillant aquaPlus Instructions For Installation And Servicing

6 Commissioning Part I

6.1 Preliminary electrical checks

Check the electrical installation by carrying out short
circuit, earth continuity and resistance to earth tests
and a check for correct polarity.

6.2 Gas supply

The complete gas installation including the gas meter
must be inspected, tested for soundness and purged in
accordance with BS 6891. In IE the current edition of
IS 813.
The gas supply to the boiler can be purged by
slackening the gas service valve beneath the boiler.
Ensure that there is adequate ventilation, extinguish all
naked flames and do not smoke whilst purging.
After purging, the gas service valve connection must be
retightened and tested for soundness. (The boiler itself
does not require purging as this will be done by the
automatic burner sequence control).

6.3 Cold water supply

Open all domestic hot water taps supplied by the boiler,
turn on the mains water supply to the boiler and open
the mains water isolating valve below the boiler.
Water will now flow through the boiler to the hot taps.
Starting with the lowest tap supplied, turn the hot taps
off one at a time until the hot water pipework is purged
of air.
Check all hot and cold water pipework for leaks.

6.4 Filling the heating system

Proceed as follows to fill the system:
• Open all radiator valves on the system.
• Check flexible filling loop is connected.
• Locate the filling valve handle on the cold water inlet
filling valve as shown (1).
• Open valve (1) fully.
• Remove filling valve handle and locate on return filling
valve (2).
• Open the valve slowly and fill the unit with water until
the required pressure has been achieved (3).
• Turn off valve (2).
• Remove valve handle and refit on cold water inlet
filling valve (1).
• Fully close valve (1).
• Bleed the air from the radiators.
• The boiler is equipped with an automatic air release
valve. To allow this to vent the boiler, the cap top must
be slackened by 1 -2 turns. (This cap must be left
slackened during operation to ensure any residual air
or system gases are released).
Instructions for installation and servicing aquaPLUS VUI 362-7
Supplied by HeatingSpares247.com

Commissioning Part I 6

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Fig. 6.1: Filling aquaPLUS boiler

6.5 Initial system flush ("cold")

The whole of the heating system must be flushed out at
least twice: once cold, and once hot as instructed later.
• Open all radiator and heating valves and the boiler CH
service valves and drain the heating system and boiler
completely from the lowest points of the system via
1/2" BSP drain taps (opened full bore to remove any
installation debris prior to lighting the boiler).
• Refill the heating system.
• Check the operation of the pressure relief valve by
rotating the knob on the valve.
• Now check the water pressure in the unit again (and
add more water if necessary).
• Close the filling valves (1) and disconnect the
temporary connection.
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