Potterton Promax 12 SL Installation And Service Instructions Manual page 45

Injector Pipe
Gas Valve
Securing Screws
Boiler Side
Fig. 53
Securing
Nut
Sensor
Leads
Condensate
Trap
Lock Nut
Condensate
Drain Pipe
© Baxi Heating UK Ltd 2007
Case Pressure Pipe
Gasket
Aluminium
Spacer
'O ring'
Electrical Plug
Service Drain
Plug
Fig. 54
15.0 Changing Components
The removal of the fan is necessary to enable the
changing of the injector pipe, condensate trap and gas
valve (see section 15.6).
15.7 Injector Pipe (Fig. 53)
1. Remove the injector pipe by pulling out from the 'O'
ring joint in the gas valve.
2. Fit the new injector pipe and reassemble in reverse
order.
15.8 Gas Valve (Fig. 53)
1. Remove the Control PCB (see Section 15.4).
2. Isolate gas supply and disconnect the gas tap by
removing the four screws.
3. Undo the case pressure pipe from the gas valve.
4. Disconnect the electrical plug from the gas valve.
5. Remove the fan (see section 15.6) and injector pipe.
6. Remove the two gas valve securing screws from
inside the air box holding the gas valve.
7. Remove the gas valve from the airbox side.
8. Remove the aluminium spacer and its gasket from
the gas valve.
Gas Valve
9. Fit the aluminium spacer and gasket to the new valve.
10. Fit the new gas valve and reassemble in reverse
Gas Tap
order.
NOTE: Check for gas tightness after replacing gas
valve.
11. Check the CO/CO
sampling point (Fig.41a) is as quoted in Section 4.0,
'Technical Data'.
12. If the ratio or level is greater than that quoted,
telephone the Technical Enquiries for further advice.
IMPORTANT: No adjustment of the gas
valve is permissible.
15.9 Condensate Trap (Fig. 54)
1. Disconnect the condensate trap from the base of the
heat exchanger.
2. Disconnect the condensate drain (outside the boiler)
from the condensate trap.
3. Undo the condensate trap lock nut and remove the
trap from the boiler. Disconnect the sensor leads.
4. Fit the new condensate trap and reassemble in
reverse order.
5. Prime the condensate trap (fill first chamber), check
for leaks.
2 ratio and CO 2 level at the flue
45