Nordyne SERIES M1B Manuel D’Utilisation

Page de 40
25
4. When call for heat is satisfi ed, the thermostat 
contacts open and the gas valve shuts off gas 
fl ow.
 WARNING:
Should overheating occur, or the gas 
supply fails to shut off, shut off the 
manual gas valve to the furnace before 
shutting off the electrical supply.
 AVERTISSEMENT: 
En case de température excessive, 
ou sail est impossible de cooper 
l’alimentation en gaz, fermer le 
robinet manuel d’alimentation en gaz 
du générateur d’sir chaud avant de 
cooper l’alimentation électrique.
FURNACE CONTROLS & FUNCTIONS
Furnace On-Off Switch
This switch turns electrical power to the furnace 
on and off. The switch must be set in the ON 
position for the furnace to operate. For M1G 
models, in warm weather there is a possibility 
of the blower turning on periodically or operating 
continuously due to a heat buildup within the 
furnace by a combination of warm weather and 
heat from the pilot. This is normal operation as 
long as there is power to the furnace and the 
furnace On-Off switch is in the ON position. If 
blower operation is not desired, the furnace On-
Off switch may be set in the OFF position to cut 
the electrical power to the furnace. See Figure 35.
Limit Control
 This furnace is protected by two high temperature 
safety limit switches. The auxiliary (upper) limit 
switch and the high temperature (lower) limit 
switch are automatic reset types. If either limit 
trips, the burner will shut off. If either limit switch 
trips off again soon after resetting, set the furnace 
furnace On-Off switch to the OFF position and 
call your authorized serviceman. See Figure 35.
Gas Valve
The gas valves for the gas furnaces are a 100% 
shut-off type and will fail safe, if for some reason 
the gas is turned off. The valve is a “step-open” 
type for M1G models and “slow-open” for M1M 
and M1B models which means it opens to a 
low-fi re position, and after a few seconds, “steps-
open” to high-fi re.
Roll Out Switch (M1G - 056 & 070)
The furnace is protected by a manual reset safety 
switch located on the bottom left hand side of 
the combustion pipe.
Oil Burner Primary Control
The primary control for oil gun furnaces starts 
the burner, monitors a safe operating cycle, and 
shuts the burner off at the end of a heating cycle. 
The control uses a light sensing transducer to 
determine if fuel ignition has been successfully 
attained. If ignition is not attained by the end of 
the safety ignition timing period, the control shuts 
the burner off and enters “lock-out.” See Figure 35.
Summer Cooling - (B, C, & D Series)
Your furnace is A/C ready, equipped with A/C 
relay and transformer. The unit is equipped to 
use a 4-wire thermostat. When using a 5-wire 
thermostat, RC and RH should be jumped (see 
instructions included with thermostat). 
Furnace
On-Off 
Switch
Oil
Pump
Fan
Control
Lower 
Limit
Switch
Upper
Limit
Switch
Oil
Burner
Control
Figure 35. Furnace Controls - Oil Furnace