Page 44 - IOM / Rooftop Smart and Linéa™ Range
HEATING OPERATION AND
ADJUSTMENTS (LG/LD UNITS)
Heating Sequence of Operation
1. On a heating demand the combustion air fan starts
immediately.
2. Combustion air pressure switch proves blower
operation, then allows power to ignition control. Switch
is factory set and requires no adjustment.
3. After a 45-second prepurge, spark ignitor energizes
and gas valve solenoid opens.
4. Spark ignites gas, ignition sensor proves the flame and
combustion continues.
5. If flame is not detected after first ignition trial, ignition
control will repeat steps 3 and 4 four more times before
locking out the gas valve.
6. Using a KP02 reset the unit faults then press the igni-
tion system reset button to reset the ignition control.
Limit Controls
Limit controls are factory-set and are not adjustable. The
primary limit is located on the vestibule panel above the
burners. The secondary limit is located on the blower deck
behind the blower housing.
GAS BURNER
GAS BURNER
GAS BURNER
GAS BURNER
GAS BURNER
TYPICAL HEAT SECTION
Figure 58
Left burner
Burner support cap
Heating Adjustment
Main burners are factory-set and do not require adjustment.
Spark gap on ignition electrode must be 3.2mm+0.8mm.
Check spark gap as follows :
1. Loosen four screws and remove burner support cap.
See figure 58.
2. Remove left burner and check gap with appropriately
sized twist drills or feeler gauges.
3. Replace burner and burner support cap. Secure cap in
place with retained screws.
