123
High Gas Pressure Switch (PS-03)
1. Turn the unit ON. Reset the lever on the switch. Gas pressure must be lower in the chamber for the
reset latch to be set properly.
2. Remove the cover. Make sure the wiring is set up for Normally Closed (N.C.) contact (
).
3. Verify the ON/OFF gas valve, and modulating valve is set properly. Refer to
4. Check for voltage:
• Back probe connector J13 pin 4 to ground. There should be
24-28V AC
.
• Back probe connector J13 pin 11 to ground. There should be
24-28V AC
.
- If the voltage reading is incorrect, check the wiring for an open or short circuit. If the wiring is
correct, the switch has failed. Replace the switch.
- If the voltage reading is correct, and the switch reset corrected the fault, there may have been an
intermittent fault.
Figure 57 - High Gas Pressure Switch
Low Gas Pressure Switch (PS-04)
1. Turn the unit ON. Verify the inlet pressure gauge is reading the correct pressure.
• Natural gas -
7 in. w.c. – 14 in. w.c
.
• Propane -
11 in. w.c. – 14 in. w.c.
NOTE: If the reading is incorrect, contact the gas supply company
.
2. Reset the lever on the switch. Gas pressure must be higher in the chamber for the reset latch to be set
properly. If the reset did not work, continue with the next step.
3. Remove the cover. Make sure the wiring is set up for Normally Open (N.O.) contact (
).
4. Check for voltage:
• Back probe connector J13 pin 3 to ground. There should be
24-28V AC
.
• Back probe connector J13 pin 10 to ground. There should be
0V AC
.
- If the voltage reading is incorrect, check the wiring for an open or short circuit. If the wiring is
correct, the switch has failed. Replace the switch.
- If the voltage reading is correct, and the switch reset corrected the fault, there may have been an
intermittent fault.
Figure 58 - Low Gas Pressure Switch
C
NO
NC
4
11
PS-03
C
NC
BL
OR
Connector J13
C
NO
NC
3
10
PS-04
C
NO
BL
RD
Connector J13