Table of Contents
Advertisement
36 FROST PROTECTION
The
boiler has built into its control system the
facility to protect only the boiler against freezing.
If the boiler global flow temperature falls below 7ºC, the
primary system pump circulates water around the water
circuit. The pump will only switch off when the global flow
temperature exceeds 10ºC.
37 COMMISSIONING AND TESTING
A. ELECTRICAL INSTALLATION
1. Checks to ensure electrical safety should be carried
out by a competent person.
2. ALWAYS carry out the preliminary electrical system
checks, i.e. earth continuity, polarity, resistance to earth
and short circuit, using a suitable meter.
38 INITIAL LIGHTING
1. Check that the system has been filled and the boiler is not
air locked - air in the boiler could damage the heat
exchanger. The air vent located in the boiler flow manifold
must never be shut off.
2. Check that all drain cocks are closed and any valves in the
flow and return are open.
3. Check that the GAS SERVICE COCK IS ON.
4. Fill the condensate trap with water before putting the unit
into operation (see frame 11 for guidance).
5. Check the indication on the pressure gauge (sealed
system installations). If the pressure is less than 0.8 bar
the system should be filled up first.
6. Switch the electricity supply ON and check all external
controls are calling for heat. Check the control panel
switch is on.
7. The boiler will commence with the ignition cycle as follows:
- After 5 seconds the system pump and if required DHW
pump/valve are energised.
- The CVI of the first module chosen to fire is energised.
32
INSTALLATION
If the boiler global flow temperature falls below 3ºC, the boiler
will fire at minimum rate in CH mode. When the global flow
temperature exceeds 10ºC the burner switches off and the
pump enters the overrun period before switching off.
B. GAS INSTALLATION
1. The whole of the gas installation, including the meter,
should be inspected and tested for soundness and then
purged in accordance with the recommendations of the
relevant standards listed on page 4.
- After 5 seconds the fan of this module is started and run
at the starting speed for 10 seconds to allow for pre-
purge. Note. The fans of the other modules also run to
balance the flueways.
- Whilst operating in pre-purge the air pressure switch,
actuated by the fan, switches from C-NO (open position)
to C-NC (closed position).
- After pre-purge the ignition spark starts and the gas valve
is opened.
- If after the safety time no ignition is detected the gas valve
is closed and the ignition spark stopped. After 5 seconds
the ignition sequence is started again.
- If after 3 attempts no ignition is detected then the module
is put in lock out mode and the relevant red push button is
illuminated on the controls panel.
- To reset the burner hold down the illuminated button and
press the reset button.
- The remaining modules will follow this ignition sequence
one at a time.
8. Operate the boiler for 20 minutes and check the gas rate.
See Frames 27 and 32 for details on how to set the boiler to
run at maximum rate. Then check the CO
minimum rate, see Frame 39.
levels at
2
-
Installation & Servicing
Hide quick links:
Advertisement
Table of Contents
