Units equipped with continuous pilot operation are fitted with
the SIT-NOVA gas valve. the gas valve has a built-in pressure
regulator and a thermo-electric ignition control for safe operation.
The valve has a step open feature (standard) for natural gas
operation. For propane, a full open feature is standard.
Explanation of the gas valve is shown in the illustration.
Step #1 - CHECKING PRESSURE
A. Turn gas connection OFF. Open gas inlet pressure
connection cap and unscrew the tap. Connect pressure
gauge at pressure tap. Read pressure.
B. If pressure measured is higher or lower than that specified
in the Pressure Table located in this manual, do not proceed
with initial operation.
C. Remove pressure gauge, screw in the tap and close with
protective cap.
Step #2 - ADJUST PILOT BURNER
The pilot burner assembly installed in your unit is tested prior
to shipment and does not require any adjustment. If adjustment is
desired, follow these instructions.
This step must be performed by a
qualified person only
A. Turn main power switch ON and turn the gas control knob
to PILOT.
B. Depress the knob for 30 seconds to establish the pilot flame.
C. Verify that pilot flame is well positioned and surrounding
the thermocouple.
D. If the flame requires adjustment, open the pilot cap on the
gas valve and adjust the screw to increase or decrease the
gas flow to achieve the right flame.
E. Close the pilot protective cap.
Step #3 - MANIFOLD PRESSURE ADJUSTMENT
The gas valve has a built-in pressure regulator and regulates the
manifold pressure according to specifications presented in the
Pressure Chart in this manual. The valve requires no adjustment.
However, if adjustment is desired, follow the instructions below.
This must be performed by a qualified person only.
A. Turn power and gas supply OFF.
B. Remove protective cap from outlet gas/manifold gas tap.
Unscrew, connect pressure gauge.
C. Turn main power switch ON, and turn the gas control knob
to ON.
D. Select program, set temperature and timer, and press the
START/STOP key. Follow oven operational instructions.
E. The gas valve will open and the main burner flame should
be established.
F.
Measure manifold pressure. If it requires adjustment, open
the cap on the pressure regulator and adjust the screw for
increased or decreased gas pressure.
DO NOT SET THE REGULATOR TO ANY OTHER SETTING
OTHER THAN TO THE DATA SPECIFIED IN
THE
PRESSURE CHART
IN THIS MANUAL.
G. Turn the gas valve OFF or to PILOT position.
H. Close the pressure regulator and manifold/outlet gas tap
with protective caps.
NOTE: If you do not understand this procedure, do not perform
any changes. Call the factory for assistance.
Step #4 - IGNITION & BURNER CHECK
For all practical reasons this will be the only check necessary
during initial operation by the installer. After the installation is
complete the oven needs to be test fired to ensure that the system is
operating properly. Follow the operating instructions posted on
the front of the unit.
The flame pattern both under hot and cold conditions should be
stable on all burner ports and there should be no lifting or blowing
after 15 seconds of operation.
See illustration in this manual for the
proper flame pattern
. There is no air shutter adjustment on these
burners and if the flame pattern does not match that shown,
contact the factory for further directions.
Make sure that the pilot burner is lighting quickly from the
electric ignitor. Then make sure that the main burner is lighting
quickly (within 4 seconds), smoothly (no harsh noise), and without
any problems. While the oven is COLD, cycle the oven ON and
OFF five times to make sure everything is working properly.
Allow the unit to heat up for 5 minutes and repeat the process.
Check the flame pattern on the burners. The flames should be
blue in color with little or no yellow in the flame. On propane gas
some yellow tipping is normal, but there should be no indication
that soot will form on the combustion chamber walls, pilot or main
burner from the yellow tipping.
Step #5 - VERIFY SEQUENCE OF OPERATION
When the Gas Combitherm is fitted with a continuous pilot and
a SIT-NOVA gas valve, the normal sequence of operation would
essentially involve igniting the pilot and switching the gas valve to
ON. The main burner would operate whenever there is demand
for heat during an active program.
However, if the continuous pilot becomes extinguished due to
interruption in gas supply or weak thermocouple signal, the
sparking or ignition system would be activated immediately to
re-ignite the pilot (the spark discharge noise can be heard). Follow
the pilot and burner ignition steps.
Operation and Care Manual #6011 • 8
1.17 - CONTINUOUS PILOT - SIT-NOVA
Pilot Gas Control
Pressure Regulator
Manifold Gas
Pressure Tap
Inlet Gas
Pressure Tap
Burner Control
Selector Knob
I n s t a l l a t i o n • S e c t i o n 1
