Keston C45 Installation And Servicing Instructions page 30

WD536
To measure CO
spigot (Figure 5.7.4 item 18). Insert the probe of a calibrated combustion analysis meter
and sample the gases as instructed in the test equipment's instructions.
When firing the boiler for the first time since installation, the CO level at high rate may be
between 100-220 ppm and between 50-80 ppm at low rate. This is due to compounds
used during manufacture curing within the combustion chamber. On boilers which have
been fired for more than one hour since installation, the CO levels should not exceed 150
ppm at high rate and 50 ppm at low rate. If CO levels above these values are
experienced, the combustion chamber and flue system should be investigated.
The C55 & C45 are factory set for combustion and should need no adjustment. However,
in the event adjustment is required.
Check combustion errors are not a result of incorrectly installed flue and/or air system,
terminal location or damage or debris on the burner. If all these factors are found to be in
order proceed as follows:
1) Set any controls to call for heat.
2) Set the boiler to run at maximum / minimum fan speed. To do this is necessary to
access the hidden buttons (behind the "KESTON" label under the display). There are five
buttons, which are used to adjust settings and provide additional boiler information. The
drawing below shows the layout of these buttons and their function.
To set the fan to maximum.
Press the "Mode" button repeatedly until the display shows "Stby".
Press and hold the "Mode" and "+" key together for 2 seconds. The display will
then show "H nn". The unit is now locked on max fan speed.
3) Measure the CO
adjustment screw (pos. 5) to produce a CO
9% for C55 with a corresponding CO level of 50 to 150 ppm for natural gas and 9.8% to
10.3% for C40P and 10% to 10.5% for C55P with a corresponding CO level of 50 to 150
ppm for LPG. NORMAL ADJUSTMENT, IF REQUIRED, SHOULD NEED NO MORE
THAN HALF OF ONE ROTATION OF THE ADJUSTMENT SCREW (pos. 5).
ADJUSTMENTS, IF MADE, SHOULD BE IN STEPS OF NO MORE THAN 1/8 OF A
TURN. YOU MUST WAIT 1 MINUTE AFTER EACH ADJUSTMENT TO ALLOW THE
SETTING TO STABILISE BEFORE TAKING A READING
To set the fan to minimum
Press the "Mode" button repeatedly until the display shows "Stby"
Press and hold the "Mode" and "-" keys together for 2 seconds. The display will
then show "L nn". The unit is now locked on min fan speed.
4) Measure the CO
for C45 and 8.3% to 8.5% for C55 with a corresponding CO level of 5 to 20 ppm for
natural gas and 9.3% to 9.5% for C40P and 9.6% to 9.8% for C55P with a corresponding
CO level of 5 to 20 ppm for LPG. THE CO2 LEVEL AT LOW RATE MUST ALWAYS BE
Installation & Servicing Instructions
Chapter 4 : Commissioning
levels in the Keston boiler remove the 1/8" plug from the flue outlet pipe
2
reading in the flue gases and adjust, if necessary, the
2
reading in the flue gases. The CO
2
The Keston C45, C40P, C55 & C55P
reading of 8.2% to 8.7% for C45 and 8.6% to
2
reading must be 8% to 8.2%
2
Page : 25