Baxi Potterton WH46, WH65 manual GAS Valve Adjustment

15. GAS VALVE ADJUSTMENT

Carry out the following operations­ in the given sequence:

1)Calibration of the maximum heat output. Check that the CO2 measured on the flue, with the boiler operating at the maximum heat output, is the same as that shown in table 1. Otherwise, turn the regulation screw (V) on the gas valve. Turn the screw clockwise to reduce the concentration of CO2 and anticlockwise to increase it.

2)Calibration of reduced heat output. Check that the CO2 measured on the flue, with the boiler operating at the minimum heat output, is the same as that shown in table 1. Otherwise, turn the offset regulation screw (K) on

the gas valve. Turn the screw clockwise to increase the concentration of CO2 and anticlockwise to reduce it.

Pi: Gas supply pressure connection point

P out: Gas pressure to burner connection point

P:Pressure connection point

for measurement of the OFFSET

Pl: Air signal input from fan

V:Gas flow adjuster screw max fire

K:OFFSET adjuster screw min fire

0310_0114

Figure 15

To simplify calibration of the gas valve, the “calibration function” can be set directly on the boiler control panel by proceeding as follows:

1) Press the keys (2-3) together until the display shows the pointer “” alongside the and symbols (about 6 seconds) (see fig. 16).

2)Press the keys to set the fan speed at the minimum and maximum heat output (%PWM);

N.b - to set the minimum and maximum heat output quickly, press the keys respectively;

3)press either of the two keys to exit the function.

0307_2201

Figure 16

INSTRUCTIONS PERTAINING TO THE INSTALLER 27 926.772.1 - GB/IE