Potthof & Co Potterton Gold HE Range Condensing Combination Boiler 33kw - Manual (Page 50)

50
© Baxi Heating UK Ltd 2012
Gas Valve
Earth Lead
Gas Feed
Elbow
Fig. 103
Power Lead
Expansion Vessel
Boiler Chassis
Lock Nut
Fig. 104
Retaining Bracket
Sensing Pipe
Venturi Inlet
Pipe
14.0 Changing Components
14.24 Gas Valve (Fig. 103)
IMPORTANT: After replacing the valve the CO
2
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 CO
2
cannot be achieved
contact the ‘heateam’ technical helpline.
14.25 Expansion 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.
Fig. 103a
Throttle
Adjustment Screw