Gas Valve - Baxi MainEco Heat 15 Installation And Service Manual

Combustion
Control Unit
Fan Gas
Supply Pipe
Electrical
Plug
Fig. 49
7215845 - 01 (08/14)
Fig. 47
View from
behind
Combustion
Control Unit
Fig. 48

Gas Valve

Securing Screws
Fan not shown for
clarity
Gas Valve
Securing Screws
Gas Inlet
Pipe
10.3.10 Gas Valve (Figs. 47, 48 & 49)
After replacing the valve the CO 2 must be checked and
adjusted as detailed in Section 10.3.13 Setting the Gas
Valve. Only change the valve if a suitable calibrated
combustion analyser is available, operated by a
competent person - see section 10.1.3.
A T25 Torx screwdriver will be required.
1. Ensure that the gas supply to the boiler is isolated.
Remove the ducts as described in Section 10.3.4
2. Disconnect the cable from the bottom of the PCB, disengage
the fan protective cover securing tab and lower the cover.
3. Taking care not to touch the PCB components, disconnect
the electrode lead, earth lead, mains power cable and the main
sensor harness from the board. Re-engage the fan protective
cover.
4. Disconnect the plug from the gas valve and undo the nut on
the gas inlet pipe at the base of the valve.
5. Remove the combustion control unit from the boiler by
releasing the over-centre catches that secure it to the heat
exchanger (Fig. 47).
6. Remove the T25 screws securing the gas valve to the fan
assembly.
7. Lift the gas valve from its seat and pull it gently downwards
to release it from the fan assembly.
8. Remove the 2 O-Rings from the gas feed pipe and replace
with new ones supplied in the kit. Take care not to damage the
O-Rings when refitting. Apply a small quantity of the silicone
grease provided to aid reassembly of the gas valve (Fig. 49).
9. Push the new gas valve onto the gas feed pipe taking care
not to damage the O-Ring seals and push home securely.
Secure the valve using the 2 T25 screws and shakeproof
washers.
10. Reassemble all components in reverse order. When a seal
kit is provided replace the existing seals with the new ones.
Inspect all other seals before reassembly and replace if
necessary. Check all the joints are tight and wires are securely
connected.
Check gas tightness & CO 2 !
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. If the boiler
will not light, or the correct CO2 cannot be achieved
contact the 'heateam' technical helpline.
See Section 10.3.13 for CO 2 check.
Maintenance 10
MainEco Heat 53