Commissioning; Commissioning Procedure - Warmworld FFC 30/60 Installation & Service Instructions Manual

Commissioning

General
The elimination of air from systems is essential to
minimise the occurrence of heat exchanger and
general system noise. It is particularly important for
lightweight boilers.
Metal swarf and flux chemicals make a very aggres-
sive mixture, the destructive nature of which can be
drastically reduced by flushing. Consequently this is
a mandatory step in the commissioning procedure.
Low water content, fabricated boilers are vulnerable
to damage by air, particularly when the system water
is 'hard'. (Contains a lot of dissolved calcium salts).
The result of this damage is evident in noisy boilers
and reduced service life.
Removal of air from a system mainly takes place
when the water is stopping, starting or not moving at
all. It is removed most easily when it is in large
bubbles, but the action of the pump is to chop it up
so that it becomes a foam, which is extremely
difficult to remove.
Two or three second bursts on the pump at the
initial stage will reduce the risk of foam formation.
Sloping the pipe runs towards the vent points will
greatly aid air removal. Sloping pipes are not just a
feature of gravity systems but can greatly aid the
pumped system because air can move towards a
vent when the pump stops.
Air is dissolved in water but is released when
heated. Always run a system at maximum tempera-
ture for at least 15 minutes to enable this potential
problem to be removed during commissioning.

Commissioning Procedure

The boiler is fitted with automatic ignition and will
start when the gas cock is open, mains is connected
to the boiler and the controls calling for heat.
NOTE:
If the boiler has just been filled with very
cold water, the built in Frost Thermostat will attempt
to fire it if it has a permanent live and no switched
live, this is completely normal. It is recommended
that the gas cock is turned off during this early stage.
Because of a built in delay, the boiler is always held
off for a minimum of 120 seconds. However, for
commissioning purposes, switch off using the
System Isolating Switch will avoid the delay.
It is strongly suggested that the following stages of
commissioning are followed, and not an immediate
connection of all services. This procedure prevents
Condensing Boiler
substantial amounts of air being dispersed through
the system as small bubbles.
Carry out electrical tests as stated in Electrical
Connections if not already done so.
With all radiator valves fully open, fill the system but
do not start pump.
Sealed Systems only :
With the temporary hose connected, fill from the
mains supply, then follow the procedure below.
Check for water soundness and rectify where
necessary.
DO NOT TURN ON GAS
Drain the system by opening all draincocks. This will
flush the system of flux and swarf.
Pour 3/4 of the inhibitor in and fill the system with
clean water and vent air from radiators and
pipework.
Sealed Systems only:
and fill to required pressure plus 0.3 bar to allow for
venting.
Switch on the electrical supply to the boiler and
switch the programmer to DHW.
Switch off after about five seconds and vent all
points again.
Repeat this for 5 minutes.
Sealed Systems only:
Turn on pump (do not turn on gas) and run for at
least 30 minutes with 3 port valve in DHW position
most of the time.
Stop pump at five minute intervals and vent until no
more air can be removed and air noises are no
longer produced at the boiler. While the system is
venting check again for water soundness.
TURN ON THE GAS
Check for gas soundness (BS 6891: 1988) in
pipework to boiler using a manometer.
Open the gas cock and after purging the system, the
boiler will light automatically.
Run system at maximum thermostat setting.
Gas soundness within the boiler should be checked
using sense of smell and/or leak detection fluid.
9
Pour in all the inhibitor,
re-pressurise if required.
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