andrews MAXXflo EVO CWH 150/302 Installation And Maintenance Manual page 65

6.2.8 GAS VALVE
• Turn off the gas supply at the burner gas cock isolator
• Carefully remove the electrical connectors of the gas valve
• Remove the allen bolts securing the gas pipe to the valve
• Release the gas valve from the venturi by undoing three cap screws
Remove venturi cap screws
• Transfer the rubber gasket to the new gas valve and orifi ce if fi tted .
• Replacement is the reverse.
• Operate the heat engine and check for gas leaks.
• After fi ve minutes check the rate and combustion is correct to the Data table. (page 11). Adjust using
the throttle adjustment screw on the gas valve if necessary. Turn clockwise to decrease CO
clockwise to increase CO
NB Valve Coil resistances are 2.8k and 1.6k ohms
6.2.8 ELECTRODE REMOVAL
These are located on the front of the heat exchanger.
Spark electrode
• Carefully pull off the electrical connectors.
• Undo the two screws retaining the bracket and withdraw.
• Replacement is the reverse ensuring that the gasket seal is placed correctly and is in good condition.
Maintenance
(see 5.0 for details)
2
Ionisation electrode Io I
65
E Electrical connector
4 4 4 x securing bolts
, anti-
2
MAXXfl o EVO 150/302