Glow-worm hxi and Gas Valve - Manual (Page 46)

Requirements
It is the Law that any replacement of parts is carried out by a
competent person approved at the time by the Health and Safety
Executive.
Before commencing with the replacement of a part the boiler
should be isolated from the electrical supply and the gas supply
should be turned off at the gas isolation valve.
When replacing a part, use only spare parts that you can be
assured conform to the safety and performance specification that
we require. Do not use reconditioned or copy parts that have
not been clearly authorised by Glow-worm.
After electrical connections have been made, checks to the
earth continuity, polarity, short circuit and resistance to earth
must be repeated using a suitable multimeter.
Unless stated otherwise, parts are replaced in the reverse order
to their removal.
After replacing these parts you MUST always test for gas
soundness and carry out functional test of the controls and
check the following:
General Inspection
After the replacement of a part, the following must be
checked.
● The integrity of the flue system and flue seals.
● The integrity of the appliance combustion circuit and
relevant seals.
● Electrical, gas and water connections.
● System pressure.
● the combustion performance, operational gas inlet
pressure and gas rates .
refer to the following procedure.
ALL MODELS
Refer to the installation and servicing instructions supplied
with your boiler to fit the replacement gas valve.
IMPORTANT. If the Burner Door was Removed
Fit the new combustion door seal kit fitted in accordance
with the instructions provided.
Re- assembly
After assembly test for gas soundness and purge in
accordance with the current issue of BS6891 or in IE, the
current edition of I.S.813 “Domestic Gas Installations”.
Do not fit the inner or front case until the commisioning has
been carried out as described in the following sections.
COMPETENCY TO CARRY OUT THE CHECK
OF COMBUSTION PERFORMANCE
NOTE: BS 6798: 2009 Specification for installation
and maintenance of gas-fired boilers of rated input not
exceeding 70kW net advises that:
● The person carrying out a combustion measurement
must be assessed as competent in the use of a flue gas
analyser and the interpretation of the results.
● The flue gas analyser used should be one meeting
the requirements of BS7927 or BS-EN50379-3 and be
calibrated in accordance with the analyser manufacturers’
requirements.
● Competence can be demonstrated by satisfactory
completion of the CPA1 ACS assessment, which covers
the use of electronic portable combustion gas analysers in
accordance with BS 7967, parts 1 to 4.
● Ensure that the gas analyser is set to the correct fuel
setting.
NOTE: Safe combustion can only be verified by measuring CO/
CO2 ratio. This must not exceed the value shown in the table on
the back page.
FLUE
ELBOW
COMBUSTION
ANALYSER
TEST POINT
FLUE
DUCT
Diagram 1
COMBUSTION
ANALYSER
TEST POINT
Diagram 2
OFFSET
ADJUSTMENT
2mm Allen Key
THROTTLE
Flat Bladed or
2mm Allen Key