Technical data

52
Does yellow flame indicator ( ) glow and flames increase in size to full rate?
Does burner flame modulate/ go out when maximum radiator temperature control is turned down to position 1 at a flow temperature of approx. 50 degree C?
Check potentiometer for partial load setting (see 5.9 C.H. range rating).
Pull of cable from NTC and short-circuit to earth. Is flame extinguished?
Check operation of burner and modulation
Sheet H
Check plug-in connections to modulating solenoid.
Replace modulating regulator of gas valve if burner still fails to increase to full rate.
Yes
No
No
No
Replace electronic boards.
Go to sheet J.
Yes
Is flame extinguished after 2nd ignition attempt, and red lockout indicator ( ) lit?
Is flame visible prior to lockout condition?
Check gas supply is live and purged.
Check connections/operation of both solenoids, replace gas valve as necessary.
Yes
No
No
Check/clean burner, ionization sensor and cable for defects, good contacts and correct position.
Check air/flue gas system is correctly fitted and not obstructed. If lockout occurs replace electronic boards.
Yes