HAMWORTHY HEATING LTD
15
PUREWELL
Vari
Heat he
500001170/K
7.2 Checks Prior to lighting the boiler
NOTE!
Refer to Appendix A for Natural Gas maximum gas inlet pressure for normal operation.
The following
checks must be made prior to lighting the boiler.
1) Ensure that the gas supply is connected but turned to the "off" position. Any unions or fittings are correctly tightened,
test points are closed, and that the ignition and probe leads are connected correctly.
2)
Ensure the electrical mains supply is correctly connected but the boiler isolator(s) are switched off. Remove the
plastic covers by turning the fixing screws anti-clockwise a 1/4 of a turn. Check all wiring loom connections such
as fan and gas valve, are correct and secure. Test the operation of the safety temperature limiter by removing the
clip & bulb from the pocket in the front of the heat exchanger, and carefully apply a heat source to the bulb. The
limit stat reset button should lift & protrude through the hole in the controls fascia. To reset, firmly press the button
through the access hole in the controls fascia using a terminal screwdriver.
If satisfactory, refit the bulb in the pocket and secure with the clip. Ensure that all limiter bulbs /sensors are fully
inserted into the pockets. The flow and return temperature sensors are located at the rear of the boiler in the flow
and return pipes.
3)
Check setting of both safety temperature limiter and control thermostat. The safety temperature limiter is set at
95°C. To remove the Safety Temperature limiter, found on the rear of the display fascia bracket. Remove the plastic
display cover by turning the 1/4 turn screws anti-clockwise a 1/4 turn. by unscrewing it’s fixing screws and unscrew the
screws securing the thermostat from its mounting plate.
The control thermostat is factory set to a flow temperature of 85°C and must be re-set to suit the application, using
button (2) on the fascia as detailed in
section 8.1.1- Controls Operation.
5) Before ignition of the boiler it must be ensured that all parts of the appliance are clean and free from debris.
Special attention should be paid to ensuring that the air inlet to the fan/venturi is clean and unobstructed.
6) Ensure the heating system circulation / shunt pump is
operational and that the pipework is free of air.
7)
To ensure correct ignition of the boiler it is
recommended to check the resistance of the hot surface
igniter. This should be checked cold, using a suitable
ohmmeter, by disconnecting the igniter from the control
panel cable and measuring the resistance across the
pins of the 2 way connector. The reading should be
between 70 and 110 ohms.
Figure 7.2.1 Location Gas Isolating
Valve/Safety Temperature Limiter
Gas
Isolating
Valve
Gas Pressure
Test Point
Position Of
Safety Temperature
Limiter Reset
Air Inlet
7.3 INITIAL LIGHTING
Only competent persons registered for working on non-domestic gas appliances should attempt the following op-
erations. Before attempting to commission any boiler, ensure that personnel involved are aware of what action is
about to be taken.
Record all readings for future reference on relevant commissioning sheet.
Allow system to warm up sufficiently to check operation of control thermostat.
A combustion check must be taken when first commissioning the boiler. A sampling point is provided in the base of the
boiler.
NOTE!
Care should be exercised when the boiler is firing as the flue components can achieve temperatures, which
could cause injury if touched.