Nu-Way MDFL 3300, Installation And Maintenance Manual

Page: 40 / 49

FAULT FINDING
Any changes made in control settings as a result of identifying and remedying fault conditions
as described below may necessitate partial or complete recommissioning. Recommissioning
shall be undertaken only by appropriately qualified and experienced personnel.
Burner Motor Fails to Start Fan Starts and Burner goes to Lockout
Possible Reason Remedy
Reinstate power supply
Check fuses
No power supply to
burner
Check burner correctly
wired
Check appliance controls
calling for heat
Check burner not locked
out
Power supply to burner
OK
Check motor overload not
tripped
Gas train disconnected Check and reconnect
Appliance controls
incorrectly set
Check and adjust as
necessary
Gas supply isolated Restore supply
Low gas pressure Check and rectify
Low gas pressure
switch incorrectly set Check and adjust as
necessary
Air pressure switch not
in start position
Check as below
Fuel selector switch
incorrectly set
Check and reset
Oil line ball valve
incorrectly set
Check and reset
Valve proving system
locked out
Check and reset
MDFL 3300 & MDFL 4000 Issue 2 08/08 Page 39
To check that the air pressure switch is in the “start”
position:
1. Switch off the electrical power supply to the
burner.
2. Remove the plug-in assembly from the control
box base.
3. Using a suitable instrument, check for electrical
continuity between the following terminal:
Landis & Staefa LFL 1.333, Terminals 13 and 14
4. If the air pressure switch is not in the start
position turn the setting dial clockwise fully to the
maximum setting. Check again for continuity
between the above terminal. If there is no
continuity the pressure switch is faulty and
should be renewed.
If a gas booster is fitted:
1. Ensure that the low inlet gas pressure switch is
not locked out.
2. Check that the booster drive belt is fitted.
3. Verify that the booster motor is rotating correctly.
1. No Ignition
Possible Reason Remedy
Air pressure switch
settings incorrect
Reset
Ignition electrode
settings incorrect
Reset
Cracked electrode
insulation
Renew electrode
HT lead disconnected
or damaged Reconnect or renew as
necessary
Ignition transformer
faulty
Renew electrode
Programming controller
faulty Check and renew as
necessary
2. No Flame – Gas Firing
Possible Reason Remedy
Gas supply isolated
Check gas supply to
burner
Gas pressure too low Investigate and remedy
Air flow incorrect for gas
flow Check and adjust as
necessary
Valves fail to open
Check wiring, replace
valves if faulty
Manual isolation valve
closed
Open valve
Carbon on diffuser Clean
3. No flame – Oil Firing
Possible Reason Remedy
Oil supply interrupted
Check oil supply to
burner
Pump coupling failed Replace
Pump drive motor (if
fitted) failed
Check wiring, fuses, etc
Oil pressure too low Investigate and remedy
Valves fail to open
Check wiring, replace
valves if faulty
Oil pump faulty Replace
Filter blocked Clean or replace
Nozzle blocked Clean or replace
Carbon on diffuser Clean