Technical data

INSTALLATION & SERVICING INSTRUCTIONS
that the boiler is factory preset to give its maximum heat output.
m Adjust the burner gas pressure to the figures shown in the
Technical Data Section. The pressure
adjustment screw location is shown on
Figure 12 . After removal of the plastic plug, turn the screw anti-
clockwise to increase the pressure, and clockwise to decrease the pressure. Check that the flames are
not yellow tipping or lifting off. If the appliance gas rate is in doubt, check by timing one or more
revolutions of the gas meter.
n Replace the plastic plug for the pressure adjustment screw, to prevent unauthorised adjustment, and
mark the appliance data badge (situated on lower right hand side of wallplate) with the arrow provided,
to show the burner pressure and heat output, that the appliance has been set to.
o Switch OFF electricity supply, disconnect pressure gauge, and replace burner pressure t est point
screw. Check for gas soundness at the test point.
p Check the operation of the flame failure device in the gas control valve as follows. With the main
burner lit, turn off the gas supply at the service cock. A "click" indicating that the device has operated
should be heard within 60 seconds of turning off the gas.
q Check that the boiler and all external controls operate satisfactorily.
r Check that the thermocouple output is in the range 6-10mV closed circuit.
Page 18
8.0 COMMISSIONING
Light the boiler and heat the system to the maximum working temperature. The maximum boiler
thermostat setting is 79°C (174°F).
Examine for leaks, turn boiler off, and drain system while hot. Refill and vent system. For sealed
systems, adjust the cold fill pressure to the required setting, and then disconnect any temporary
connection to the mains water supply.
8.1 SYSTEM BYPASS
It is important that the water flow rate through the boiler does not fall below the figure shown in the
Technical Data Section, at any time when the boiler is firing. Therefore a bypass must be fitted.
To adjust the bypass, fire the boiler with a full load, ie central heating and domestic hot water both on,
and the bypass fully closed. Adjust the pump to give a temperature rise of 11 °C (20°F) across the
system. The system should then be switched to minimum load, ie central heating only with the radiator
valves turned off. If noise is experienced under these conditions, the bypass valve should be gradually
http://www.partsarena.com/baxi/System/DATA/Dx/DS1/installation/2102/I01-2102/I01-2102.htm (26 of 44)14/10/2004 17:30:48