Lennox FCM 85 Installation, Operating And Maintenance page 71

HEATING : GAS BURNER
BURNER SAFETY CHECKS
Smoke extractor pressure switch Test.
- With the gas burner running, disconnect the flexible tube
fitted to the pressure taping on the pressure switch (Fig.
23).
- The Flame must disappear and the extraction fan must
carry on running.
- However, NO fault will be displayed (Gas ignition control
block or CLIMATIC).
Fig. 23
- After reconnecting of the tube, the Burner will restart after
a period of 30 to 45 seconds pre-ventilation.
Gas pressure switch test
-With the gas burner running, close the shut off valve
located before the rooftop. (fig. 24)
Fig. 24
-The burner stops completely.
-However, No fault light will be displayed on the Gas
ignition control block. After 6 Minutes, the CLIMATIC will
display a fault.
-Reset the CLIMATIC.
FLEXYII_WSHP-IOM-0909-E
Ionisation Probe test
- With the gas burner running, disconnect the terminal plug
coming from the ionisation probe to the gas ignition control
box.
-The flame disappears
-The fan is still running and attempting to restart the burner
(restart cycle 30 to 45 seconds).
-if the ignition probe is not reconnected at the end of the
ignition sequence the burner will stop completely.
-The fault light on the gas ignition control block is ON.
-Manually reset the gas ignition control block to eliminate
the fault
IN CASE OF PROBLEMS REFER TO THE START UP
SEQUENCE FLOWCHART NEXT PAGE
Page 69