Flue Gas Analysis; Cleaning The Siphon And Heat Exchanger; Cleaning The Siphon - Worcester Greenstar i System ErP Series Installation, Commissioning And Servicing Instructions

Service and spares
7.5

Flue gas analysis

NOTICE: Combustion testing
▶ Combustion testing must be carried out by a
competent person. Testing must not be attempted
unless the person carrying out the combustion check
is equipped with a calibrated Combustion Analyser
conforming to BS 7927 and is competent in its use.
Ensure that the gas inlet pressure is correct before
continuing, ( section 6.5.1).
▶ Refer to section 6.5.9 for how to set the appliance to maximum and
minimum outputs for the flue gas analysis and check that the
readings conform to those given in tables 43 and 44. In addition to
the CO and CO/CO ratio checks also check the minimum and
2
maximum CO percentage reading.
2
NG Appliances
Output CO Reading
2
Maximum setting Between
(should be measured 9.0 and 10.8%
after 10 minutes)
Minimum setting Minimum lower than
(should be measured the maximum reading
after 10 minutes) taken but above 8.0%
and less than 10.6%
Table 43 NG CO/CO settings
2
LPG Appliances
Output CO Reading
2
Maximum setting Between
(should be measured 10.2and 11.8%
after 10 minutes)
Minimum setting Minimum lower than
(should be measured the maximum reading
after 10 minutes) taken but above 9.5%
and less than 11.6%
Table 44 LPG CO/CO settings
2
If the CO is out of tolerance then please check:
2
▶ The gas inlet pressure,
▶ The gas rate,
▶ The fan test pressure,
▶ The flue and air intake, plus any possible blockages in the condensate
disposal.
▶ For leaks or obstructions in the gas way,
▶ That the injector is clean.
▶ The condition of burner.
After all checks have been and the CO
gas valve must be replaced.
52
CO Reading
Less than
200ppm
Less than
200ppm
CO Reading
Less than
250ppm
Less than
250ppm
is still out of tolerance then the
2
7.6

Cleaning the siphon and heat exchanger

NOTICE: Gaskets
▶ The burner and electrode assembly gaskets must be
replaced if the air/gas manifold clamping plate is
loosened or removed.
There is an optional tool available to assist in cleaning the
heat exchanger, part number 7 733 600 091.
The following items will have to be removed to gain access to the heat
exchanger for cleaning:
▶ Remove the case.
▶ Lower the control panel into the service position.
▶ Disconnect electrical wires to the fan, ignition transformer, spark
electrodes, flue overheat thermostat, main heat exchanger
temperature sensor and flow pipe temperature sensor.
▶ Flueway
▶ Fan assembly
▶ Ignition transformer
▶ Spark electrode assembly
▶ Burner housing, burner and gasket
Refer to sections 7.7.4 to 7.7.7 for instructions on how to remove the
items to gain access to the heat exchanger channels so that the heat
exchanger can be cleaned
7.6.1

Cleaning the siphon

Access to the siphon
▶ Loosen the captive screw securing the control panel [1].
▶ Hinge open the control panel [2] into service position.
1
2
Fig. 64 Access for removing siphon
Greenstar i System - 6 720 806 945 (2015/07)
ErP