Glow-worm 56-2 Back Boiler - Manual (Page 12)

12 221781A
6 Commissioning
Diagram 6.1
'D' PIEZO
UNIT BUTTON
'L'
BOILER
DATA
BADGE
SETTING
POINT
'M' VIEWING
WINDOW
6074
'E' PILOT BURNER
'N'
PILOT
ADJUSTMENT
SCREW
'F'
GOVERNOR
ADJUSTMENT
COVER
SCREW
'A'
GAS VALVE
CONTROL
KNOB
SETTING
POINT
OFF
PILOT/IGNITION
MAIN BURNER
'G'
BURNER
PRESSURE
TEST POINT
'K' GAS
SERVICE
COCK
'B'
THERMOSTAT
CONTROL
KNOB
6.1 Commissioning the Back Boiler
The Back Boiler is fitted with a flue blockage safety device which
will shut it down if there is a lack of oxygen.
The flue blockage safety device assembly incorporates the
electrode, thermocouple and pilot assemblies.
Note: The flue blockage safety device sensing tube is supplied
with the fire front.
The lighting, testing of the boiler and commissioning of the
system can continue, but the lighting of the boiler must be
repeated after fitting the sensing tube.
If the back boiler shuts down frequently for no apparent reason
the first things to be checked are the chimney and air inlets into
the room. Any problems found must be put right, by a competent
person, before the back boiler is used again.
Also, when sensing tube is fitted, check that the filter is not linted
up, see diagram 9.4.
The flue blockage safety device MUST NOT be adjusted or
disconnected.
If replacing use only the correct and approved parts.
Before commissioning the back boiler, the whole of the system
should be thoroughly flushed out with cold water with the
circulation pump removed. Replace the pump, fill the system
and examine for water soundness. Vent air from the system
and pump.
CAUTION. The following work should be done by a competent
person.
Identify the back boiler controls by reference to diagram 6.1.
Open windows and put out all naked lights, cigarettes etc.
Test the gas supply for soundness. Purge air in accordance
with the current issue of BS6891.
Check that the electrical supply to the back boiler is switched
off.
Set the control thermostat control knob “B” to “Off” that is, fully
anti-clockwise.
Make sure the control thermostat phial is correctly located, see
Section 5.6.
Remove the back boiler burner pressure test screw “G” and
connect a suitable pressure gauge.
If flue blockage safety device sensing tube is not fitted, remove
the plastic ferrule from the bulkhead connector on the air duct,
replace ferrule after testing/commissioning.
Turn gas service cock “K” to Back Boiler only “On” position, see
diagram 6.2.
Push in slightly and turn gas valve control knob “A” anti-
clockwise until * is against the setting point, now fully push in and
hold, at the same time press and release piezo button “D” until
the pilot burner “E” lights, view through window “M”.
Note, at this stage air may be present in the pilot supply so this
operation may need to be repeated.
When the pilot burner lights, keep gas valve control knob “A”
fully pushed in for about 15 seconds. If the pilot burner fails to
stay alight, repeat the lighting procedure but now keep the
control “A” knob pushed in for a little longer.
Check that the pilot flame is stable and has a length as shown
in diagram 6.3.
Push in slightly and turn gas valve control knob “A” anti-
clockwise until
is against the setting point.
If the gas valve control knob “A” is turned until is against the
setting point, a safety lock prevents it being turned on again until
the thermocouple has cooled. NO ATTEMPT SHOULD BE
MADE TO TURN THE CONTROL KNOB “A” UNTIL AT LEAST
3 MINUTES HAVE GONE BY.
Switch on electrical supply and set any remote controls that is,
clock, thermostats, and the like, for heating. Refer to control
manufacturers’ instructions for specific detail
Turn control thermostat knob “B” clockwise until “MAX” is
against the setting point. The main burner should now light.
Test for gas soundness using a suitable leak detection fluid.
The back boiler is supplied preset to the maximum heat input but
may be adjusted to suit design requirements. Refer to Data
Label or Range Rating Table for details.
If adjustment is required, TEN MINUTES after lighting, remove
cover “F” and turn adjustment screw, anti-clockwise to suit
system design heat input.