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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
Saunier Duval.
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.
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”.
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.
Diagram 1
Diagram 2
b
