Casing Removing; Combustion Check And Setting The Air/Gas Ratio Valve - Glow-worm Ultracom 2 24cxi Installation And Servicing

MAINTENANCE
18.2

Casing removing

18.2.1 front panel
1
B
A
Key
1 front panel
2 Front panel retaining screw
• Undo the two screws (2) on the underside of the front panel
and remove the front panel (1).
18.2.2 Control box
1
Key
1 Control box
• Position the control box (1) into the service position.
- 40 -
Supplied By www.heating spares.co Tel. 0161 620 6677
2
A
18.3 Combustion check and setting the air/gas
ratio valve
18.3.1 Competency to carry out the check of
combustion performance
BS 6798: 2009 Specification for installation and
i
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.
• Select the "
+ ", constant central heating with DHW
function by pressing the "
commissioning section. The boiler should fire automatically.
Safe combustion can only be verified by measuring
i
CO/CO2 ratio. This must not exceed the value
shown in the table opposite.
18.3.2 Preliminaries
Prior to, during servicing and after any maintenance or changed
parts, 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, refer to the following
procedure.
• The operational gas inlet pressure and gas rates, refer to
the commissioning section paragraph 12.5. Correct any falt
before continuing.
Combustion check and setting the air/gas ratio
• Remove the front casing panel, see diagram above and
hinge down the control box. Taking care not to touch any
internal components, proceed as follows:
• Connect the CO2 combustion analyser to the relevant test
point, see diagram opposite.
" button repeatedly, refer to
0020085231_02 - 05/10 - Glow-worm