Nordyne SERIES M1B Manuel D’Utilisation

Page de 40
27
120 VAC Is Available At AMP Plug - Ignitor 
Does Not Heat Up
1. Disconnect power to the furnace.
2. Disconnect AMP plug to the ignitor, and check 
ignitor resistance with an ohm meter. Set on 
RX1 scale.
•  Normal reading should be 40 - 75 ohms.
•  If above or below this rating at room tem-
perature change ignitor.
3. Check for continuity from ignitor receptacle to 
burner.
Main Flame Ignites - Burner Locks Out
•  Ignition control is not properly grounded.
•  Defective ignition control.
•  Improper polarity of 120 volt power supply.
•  Ignitor has hairline crack.
•  Improper gas pressure or burner air adjustment 
is not allowing fl ame to contact ignitor tip for 
fl ame rectifi cation.
•  Misaligned ignitor does not allow fl ame to 
contact ignitor tip for fl ame rectifi cation.
Burner Short Cycling - Thermostat Calls for 
Heat, Limit Switches Closed
•  Check for polarity.
• Check ground.
• Check fl ue.
•  Check combustion air.
•  Check gas pressure.
• Check orifi ce.
•  Check the position of ignitor, a normal reading 
should be 40-75 ohms.
24 Volts Supplied To Gas Valve During Ignition 
- No Main Gas Flow
• Gas valve may be defective. Replace if 
necessary.
• Gas piping may be plugged. Check for 
adequate gas supply to gas valve at union. 
Burner Operates - Insuffi cient Heat
• Check thermostat for proper setting and 
location. Thermostat should not be located 
where it will be affected by another heat source.
•  Check for clean fi lter and proper air fl ow.
•  Check burner for proper gas fi ring rate.
•  Be sure unit is not undersized for its thermal 
load.
• Check thermostat anticipator. The nominal 
setting is 0.4.
Burner Flame Without Motor Running
•  Gas valve stuck open, check gas valve for 
proper operation (replace if necessary) and 
inspect heat exchanger.
•  Check for 115 volts to the combustion blower 
motor; replace if necessary.
•  If no power to combustion blower then check 
wiring and control module; replace if necessary.
Circulation Air Blower Will Not Operate Even 
Though The Burner Does Operate
• Check thermostat G connection.
•  Check wiring to motor.
•  Check for a defective motor.
Oil Gun - Honeywell R7184 or Beckett 7505 
Controls Only - M5S Series.
Burner does not start with a call for heat.
•  Check the electrical supply to furnace.
•  Verify the furnace door switch is in the ON 
position.
•  Check for line voltage (115 VAC) at the oil 
primary control.
•  Check indicator LED with burner off, no call 
for heat (no fl ame). See Table 9 (page 29).
-  If green LED indicator is on, the cad cell is 
seeing stray light or the cad cell of controller 
is defective.
-  If green LED indicator is off, go immediately 
to step 5.
-  If LED indicator is fl ashing (red or green on 
Beckett 7505 control), refer to the next step 
1 below - Reset primary control.
• Jumper T to T terminals on primary control.
-  If burner starts, check thermostat or limit 
wiring connections.
-  If burner does not start, turn off power. Check 
all wiring connections.
-  If burner does not start, replace primary 
control.
Burner starts and then locks out on safety 
with Honeywell R7184 LED indicator fl ashing 
½ second on, ½ second off. For Beckett 7505 
control, the red LED will fl ash.
1.  Reset primary control: To reset the control 
from (soft) lockout, the button needs only to be 
pressed and released. If the R7184 control is 
in restricted mode, press and hold the button 
for 45 seconds - until the LED fl ashes once. If 
the 7505 control is in restricted mode, press 
and hold the button in for 15 seconds until the 
red  turns off and the yellow LED turns on.
NOTE: Restricted Lockout: If the control locks 
out three times in a row without a complete heat 
cycle between attempts, the lockout becomes a 
restricted (hard) lockout.
2. If the LED indicator stops fl ashing and the 
ignition remains off, the primary control could 
be defective. If line voltage is present at the 
igniter terminals, and there is no ignition, 
the igniter is likely defective and needs to be 
replaced.
3. If the  stops fl ashing, burner turns on, but the 
control locks out again, check the cad cell. If