35
Response 80 / 100 / 120
- Installation
1. Isolate the electricity supply at the switched spur.
Note. T
urning the boiler on/off switch does not isolate the permanent live supply to the boiler.
2. Turn off the gas supply.
Note.
In order to assist fault finding, the printed circuit boards are fitted with indicator lights . Full details are found in the Fault-
Finding section.
IMPORTANT. When work is complete the sealing panel must be correctly fitted, ensuring that a good seal is made.
THE BOILER MUST NOT BE OPERATED IF THE SEALING PANEL IS NOT FITTED.
WHEN REPLACING ANY
COMPONENT:
54
GENERAL
REPLACEMENT OF COMPONENTS
1. Place a plastic sheet or similar beneath the boiler
and remove all visible loose deposits from the
heat exchanger fins, using a suitable brush.
2. Take care to clean debris from the ledge inside
the combustion chamber.
51
CLEANING THE HEAT EXCHANGER
SERVICING
SER
VICING
After any servicing, reference should be made to:
!
Tables 2 and 3, page 3 (or the data plate), which quote
details of the burner pressures for the boiler models.
!
Frame 45 'Gas rate.'
Note that the pressure is set by the gas valve according to
fan speed, which in turn is controlled by reference to boiler
temperature and mode (CH/HW) thus the burner pressure
should be checked at maximum demand for CH or HW as
appropriate.
Frame 82 deals with possible causes of incorrect burner
pressure.
52
RE-ASSEMBLY
5. Refit the fan venturi and sensing pipe assembly,
tightening all 3 screws on the venturi and the 2 screws
on the sensing pipe. (Ensure the 'O' ring seal is in place
before clamping the sensing pipe to the manifold
6. Refit the boiler sealing panel.
IMPORTANT. Ensure the boiler sealing panel is correctly
fitted and that a good seal is made.
7. Refit the boiler front panel.
8. Turn on the gas supply at the gas service cock.
9. Reconnect the electrical supply.
Re-assemble the boiler in the following order:
1. Refit the burner, renewing any damaged or
deteriorating sealing gaskets.
2. Reconnect the 2 ignition leads and the detection lead.
3. Reconnect the fan electrical harness.
4. Ensure that the fan 'O' ring seal is in place then refit the
fan, engaging it in the bayonet fixing and locating it in
the retaining clip on the burner mounting plate.
53
BURNER PRESSURE CHECK