25
fig. 34
GW 410/0
5. Commissioning
5.1 Preliminary electrical checks
Check the electrical installation by
carrying out short circuit, earth conti-
nuity and resistance to earth tests and
a check for correct polarity.
5.2 Gas supply
The complete gas installation inclu-
ding the gas meter must be inspected,
tested for soundness and purged in
accordance with BS 6891.
The gas supply to the boiler can be
purged by slackening the gas service
valve beneath the boiler (1, fig. 34).
Ensure that there is adequate ventila-
tion, extinguish naked flames and do
not smoke whilst purging.
After purging, the gas service valve
connection must be re-tightened and
tested for soundness.
(The boiler itself does not require pur-
ging as this will be done by the auto-
matic burner sequence control).
5.3 Water supply
Open all domestic hot water taps sup-
plied by the boiler, turn on the mains
water supply to the boiler and open
the mains water isolating valve below
the boiler (2, fig. 34).
Water will now flow through the boi-
ler 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 pipework for
leaks.
