Sensing Pipe
Power Lead
Earth Lead
Gas Feed
Elbow
Fig. 103
Venturi Inlet
Pipe
Gas Valve
Throttle
Adjustment Screw
14.0Changing Components
14.24Gas Valve (Fig. 103)
IMPORTANT: After replacing the valve the CO2 must be checked and adjusted as detailed in Section 15.0 Setting the Gas Valve. Only change the valve if a suitable calibrated combustion analyser is available, operated by a competent person - see section 13.1.
1.Turn the gas cock off and undo the nut on the gas feed elbow under the boiler.
2.Remove the screws securing the gas valve to the boiler bottom panel.
3.Pull off the power lead, earth lead and sensing pipe.
4.Undo the nut on the gas pipe at the gas/air inlet and the gas valve. Remove the pipe, taking care not to lose the sealing washers. Remove the valve.
5.Reassemble in reverse order, ensuring that all seals are in place and the injector is fitted.
NOTE: To assist the boiler to light prior to final setting, use a suitable hexagon key to wind out the Throttle adjustment screw until it is flush with the valve body, then turn the screw 4 full turns clockwise (Fig. 103a). If the boiler will not light, or the correct CO2 cannot be achieved contact the ‘heateam’ technical helpline.
Retaining Bracket
Boiler Chassis
Fig. 104
Fig. 103a
Expansion Vessel
Lock Nut
14.25Expansion Vessel (Fig. 104)
1.Drain the primary circuit and undo the nut on the vessel connection pipe.
2.Undo and remove the locknut securing the vessel spigot to the boiler air box.
3.Remove the bracket and vessel from the boiler.
4.Locate the retaining bracket on the upper flange of the vessel and fit to the boiler.
5.Reassemble in reverse order.
50© Baxi Heating UK Ltd 2012
