Water Circulation System; Commissioning The Boiler; Boiler Checks Prior To Lighting - Hamworthy Wessex 100 M100 Installation, Commissioning And Servicing Instructions

11.3 Water Circulation System

For design see Section 8:WATER SYSTEM.
The system should be thoroughly flushed out with
cold water without the pump in position. Ensure all
the valves are open.
With the pump fitted the system should be filled and
air locks cleared. Vent the radiators and check for
leaks.
If the system is unvented the pressurisation unit
should not be utilised for the initial filling.
should be carried out using a WRC approved double
check valve and temporary-filling loop.
In order to comply with local Water Authority
Regulations, this loop must be disconnected when
filling is complete. Water treatments should not be
fed through the pressurisation unit unless permitted
by the manufacturer.
Check the expansion vessel cushion pressure as
detailed by the manufacturer's Installer's Guide.

11.4 Commissioning the Boiler

A competent person holding 'CORGI' registration
MUST be responsible for the commissioning of this
boiler. Before attempting to commission any boiler,
ensure that personnel involved are aware of what
action is about to be taken and begin by making the
following checks: -
1) Flueway passages to chimney are clear.
2) Adequate ventilation as per Section 7: Air
Supply (p8) exists in the boiler house.
3) The system is fully charged with water, ready to
receive heat. All necessary valves are open and the
pump is circulating water.
4) The pipework
installed to Hamworthy Heating recommendations in
such a way that water flow rates will be in
accordance with Figure 2.2 (p4).
5) The gas supply pipework is clear of any loose
matter, tested for soundness and purged.
6) The condensate discharge is connected to a
drain.

11.4.1 Boiler Checks Prior To Lighting

NOTE! Refer to Figure 2.2 (p4) for maximum gas inlet
pressure for normal operation. Information relating to
propane firing can be found in Appendix 'A' (p30).
1) Gas supply is connected but turned to the "off"
position. Check that the ignition and probe leads are
HAMWORTHY HEATING LTD
and valve arrangement
connected correctly. Ensure Hot Surface igniter and
sensing probe assembly are not cracked or broken.
2) Ensure electricity is connected but switched off
and 2A fuse on boiler fascia removed. Check that the
plug/socket gas valve PCB connection is correctly
located and that the sensor and thermostat bulbs are
fully inserted into the boiler pocket. Reset and test the
operation of the temperature limiter by firmly reset
pressing pin (in controls fascia), removing the clip and
bulb from the pocket and carefully applying a heat
source to the bulb. The reset button should operate. If
satisfactory, refit the bulb in the pocket and secure with
This the clip.
3) If a Sequencing Interface Module is fitted to the
boiler control panel, locate the hand/auto switch 'SW2'
at the top of the boiler main PCB, and set it to the
'hand' position to override operation of the Sequencing
Interface Module for the purposes of commissioning.
4) Check setting of both temperature limiter and
control thermostat. The temperature limiter must be
set at 100°C maximum. This can be achieved by
removing plastic cover (unscrewing) if fitted. Drop
down fascia on controls housing, undo holding nut
and withdraw into the controls housing. Adjust if
required and refit in reverse order to that above. Set
control thermostat to required temperature. Ensure
limits are set if required (refer to appendix B). Set
Hi/Lo thermostat to required temperature. This is
generally set 3-5°C below control thermostat
temperature.
NOTE! It is generally recommended that the minimum
return temperature to a non-condensing boiler is 50°C.
5) With the fascia panel down, access the terminal
connections at the bottom of the main PCB.
Figure 9.1 shows the correct location of incoming
wires. Remove link on terminals R1 - R2 (black
wire) on the PCB and insert a multi-meter set to
read DC µA.
is
6) The Wessex boiler utilises both high and low fire
gas rates, dependant upon the control thermostat
demand, ignited by Hot Surface Ignition (HSI), see
Figure 14.1 (p25). To ascertain which type of gas
valve is fitted, refer to Figure 11.2 (p18). The
method of low fire and high fire adjustment is
explained on this data sheet. This procedure should
be read and understood for later use when required.
7) Ensure air pressure switch sensing tubes are
correctly fitted, without twists or kinks, between the
switches in the control panel and the airflow-sensing
device on the inlet damper assembly. Refer to
Figure 14.2 (p25) for provisional pressure switch
setting(s).
Ensure that the inlet damper mechanism is intact and
free to operate over its range, see Figure 11.4.5 (p19).
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WESSEX 100 M 500001080/F