HAMWORTHY HEATING LTD
15
PUREWELL VariHeat he
500001155/F
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.
If satisfactory, refit the bulb in the pocket and secure
with the clip. Ensure that all thermostat 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 temperature limit thermostat
and control thermostat. The limit thermostat is set at
95°C. To remove the limit thermostat, found on the rear of
the display fascia bracket removing the plastic display
cover and unscrew the fixing 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
the process detailed in
section 8.7.2.1 - Controls
Operation
4)
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.
7.3 INITIAL LIGHTING
Only competent persons registered for working on non-domestic gas appliances should attempt the following
operations. 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.
Figure 7.2.1 Gas Isolating Valve
Boiler On/Off - Enter - Reset
Gas
Isolating
Valve
1)
Ensure that the gas supply is connected but turned to the "off" position. Any unions or fittings are correctly tight-
ened, 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. Check all
wiring loom connections such as fan and gas valve, are correct and secure. Test the operation of the safety tem-
perature limit thermostat (Limit Stat) 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.
Gas Pressure
Test Point
Position Limit
Thermostat
Reset
Figure 7.3.1 Boiler Facia Display
Position Of
Viewing
Window
