Potterton Derwent Compact Plus Installation, Operation & Maintenance Manual page 25

POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
DERWENT COMPACT PLUS - CONDENSING
Stage 6
Pilot burner lights.
Main burner does not
light.
Control box does not
lockout.
Stage 7
Pilot burner lights.
Main burner lights.
Control box locks out.
Stage 8
Boiler works on low load
only
Stage 9
Boiler work on high load
a) Check main burner gas valve is open.
b) Check electrical continuity to main gas valve.
c) Check operation of gas valve and replace if necessary.
d) Check control box. Replace if necessary.
a) Check ignition of main flame is smooth and reliable.
b) Check voltage supply for interference.
a) Check the 230V supply
b) Check the damper position
c) Check the main gas valve adjustment at 16.5 mbar
d) Check the air pressure switch for full load
e) Check the rheostat position
a) Check the main gas valve to be at 10.5 mbar
SECTION 5
PAGE 23