Cleaning The Heat Exchanger; Cleaning The Siphon - Bosch Worcester Greenstar CDi Compact ErP Series Installation, Commissioning And Servicing Instruction

▶ Set the boiler to minimum power by pressing the down arrow button.
– "Min" will flash at the bottom left of the screen.
– The boiler will take 30 to 35 seconds to ramp down to minimum
output.
– Allow the boiler to stabilise at minimum output.
▶ Check the CO/CO readings against those in tables 27 and 28
2
▶ Return the boiler to maximum, by pressing the UP arrow button, and
re-check the CO/CO .
2
– "Max" will flash at the bottom left of the screen.
– The boiler will take approximately 30 to 35 seconds to ramp up to
maximum output.
– Allow the boiler to stabilise at maximum output.
▶ If correct, press the button and the boiler will return to normal
operation.
▶ Re-assemble and refit boiler case.
NOTICE: Minimum CO
▶ The minimum CO
2
that the maximum CO
NG Appliances
Output CO
2
Maximum setting Between 8.5 and 10.1.
(measured after
10 minutes
Minimum setting A minimum 0.2 lower than the
(measured after maximum reading taken but
10 minutes above 7.5%
Table 27 NG CO/CO settings
2
LPG Appliances
Output CO
2
Maximum setting Between 9.8 and 11.1.
(measured after
10 minutes
Minimum setting A minimum 0.2 lower than the
(measured after maximum reading taken but
10 minutes above 8.5%
Table 28 LPG CO/CO settings
2
Example of a Natural Gas appliance reading:
• Maximum CO reading taken = 9.5%
2
• The minimum CO reading must be between 8.0% and 9.3%
2
(a minimum 0.2 lower than the maximum reading of 9.5%)
If the CO is out of tolerance then please check:
2
▶ the gas inlet pressure,
▶ the gas rate,
▶ the fan test pressure,
▶ the condition of burner,
▶ 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.
After all checks have been and the CO
gas valve must be replaced.
CDi Compact ErP - 6 720 813 276 (2015/07)
2
reading must be at least 0.2 lower
reading.
2
Reading CO Reading
Less than 200ppm
Less than 50ppm
Reading CO Reading
Less than 200ppm
Less than 50ppm
is still out of tolerance then the
2
7.7

Cleaning the heat exchanger

NOTICE: Gaskets and seals
▶ Replace the burner and electrode assembly gaskets
and the Flueway sump seal after cleaning the heat
exchanger.
Do not attempt the cleaning procedure unless new
gaskets and seals are available.
There is an optional tool available to assist in cleaning the
heat exchanger, part number 7 746 901 479
The following items will have to be removed to gain access to the heat
exchanger for cleaning:
▶ Lower the control panel into the service position.
▶ Remove the case.
▶ 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 7.8.10 to 7.8.14 for instructions on how to remove
the items to gain access to the heat exchanger channels so that the heat
exchanger can be cleaned
7.7.1

Cleaning the siphon

1. Protect the controller from water ingress and disconnect the black
discharge hose from the wall frame connector.
2. Rotate the siphon body clockwise to release the bayonet connection.
3. Pull the siphon body down and away from the boiler.
▶ Empty the water and debris into a suitable container.
▶ Visually inspect the siphon to ensure that it is clean and free from
debris.
3.
Fig. 72 Cleaning the siphon
Refitting the siphon
▶ Fill siphon with 200 to 250 millilitres of water.
1. Push the siphon up onto the sump assembly until it fully engages with
the sump connection.
NOTICE: Do not use solvents, adhesive or lubricant
when pushing the pipe onto the rubber connector.
SERVICE AND SPARES
2.
1.
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