Lennox LSS-35CN Installation Instructions Manual page 31

Electronic Appliances
Step 5. SIT Systems - Refer to Figure 52 and
the instructions provided with the kit. Discard
all removed components.
Step 6. Shut off the gas supply to the valve and
shut down the electric supply.
Step 7. See Figure 52. Using a Torx T20, or
slotted screwdriver, remove and discard the two
(2) pressure regulator mounting screws, pres-
sure regulator tower, the diaphragm assembly
(A) (if applicable) and the spring (B).
Step 8. Ensure the rubber gasket (C), which is
pre-fitted as part of the assembly, is properly
positioned (see Figure 52 ).
Step 9. Install the new Stepper Motor pressure
regulator assembly using the supplied screws
as shown in Figure 44. Tighten screws securely
(reference torque = 25 lb. in.).
Step 10. Install the enclosed identification label
to the valve body where it can be easily seen.
Step 11. Make Stepper Motor and valve electri-
cal connections.
Step 12. Attach manometer to the manifold side
pressure test fitting and verify manifold pressure
reads 3.5 inches water column (0.87 kPa) for
natural gas, and 10.0 inches water column (2.49
kPa) for propane gas (see Figure 52 ).
Step 13. See Figure 53 and replace the pilot
orifice as follows: Remove the pilot hood
assembly to access the hexed pilot orifice.
Remove and replace the orifice with the one
provided with the kit. Exercise extreme care
to prevent damage to or breakage of the
ignitor assembly.
Pressure
Regulator
Manifold (Out)
Test Port
Line (In) Test Port
Figure 52
Pilot
Orifice
Figure 53
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Tower
Gas Valve
Figure 54
Connect GTMS
Wire Harness
Pressure Regulator
Mounting Screws
(Torx-T20)
(A) Remove Diaphragm
(B) Remove Spring
Install New:
Pressure Regulator Tower
(C) Rubber Gasket
Rear Main Burner Orifice
Front Main
Burner Orifice
31