Keston 50 - GC Installation And Servicing Instructions page 45

WD50/2/1997 Chapter 6 : Servicing
c. If necessary, either due to discolouration or a high pressure differential between
points A & B in the pre-service checks, clean the burner with a mild household
detergent and rinse under a hot running tap.
d. If necessary, either from visual inspection or a high pressure differential between
points B & C in the pre-service checks, clean the heat exchanger using a suitable
stiff plastic bristle brush, vacuum out any large particles and flush the heat
exchanger with fresh water until the water flowing from the condensate drain is
clear. When brushing the heat exchanger take care not to damage the
condensing plug in the lower half of the heat exchanger.
e. Remove the condensate trap (Section 7.10) and unscrew the cap. Clean by
flushing through with clean running water. Reassemble in reverse order.
f. Check the electrodes mounted on the burner head. If the points are damaged or
burnt replace them.
Check that the spark gap measures 4 mm.
g. Replace the burner head, renewing any gasket as necessary, and reconnect the
gas/air supply and the ignition lead. Ensure the flanged gas/air supply joint is air
tight.
h. Turn on the electrical supply to the boiler and allow the boiler to reach operating
temperature levels.
i. Check for gas leakage around the burner head, air/gas flexible hose to the burner
head and ignitor plug if they have been removed.
j. Visually inspect the burner through the glass spy hole at the burner head (a small
mirror will prove useful).
k. Recheck the burner pressure by following the procedure detailed in Section 4.7
Installation & Servicing Instructions
The Keston 50, 60 & 80 Condensing Boilers
Page : 42