Knight 100 Series, Service Manual

Page: 49 / 52

3
Troubleshooting
(continued)
49
Table 3-6 Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE CORRECTIVE ACTION
Vent/Air Intake Length
or Obstruction
• Refer to Section 3 - General Venting of the Knight Fire Tube Boiler Installation and Operation
Manual for the proper venting and air intake methods for the Fire Tube Boiler.
• Check for obstructions at the vent/air intake terminals.
Gas Supply Pressure
• Refer to Section 7 - Gas Connections of the Knight Fire Tube Boiler Installation and Operation
Manual for the proper gas supply for the Fire Tube boiler.
Dirty/Damaged Burner
• Refer to the Maintenance Section of this manual for burner removal and cleaning procedures.
• Replace burner if necessary.
Gas Valve Adjustment
• Refer to the Troubleshooting Section of this manual for the gas valve adjustment procedure.
Service Manual
Table 3-5 Flue Products Chart
You must replace the combustion plug
in the vent connector to prevent flue gas
spillage into the room. Failure to comply
could result in severe personal injury, death,
or substantial property damage.
Natural Gas
Input
Rate
Target Range
CO
2
O
2
CO
2
O
2
High Fire
9.2% 4.5% 9.0% - 10.5% 2.1% - 4.8%
Low Fire
9.0% 4.8% 8.8% - 9.5% 3.9% - 5.2%
CO levels should be less than 200 ppm.
Propane
Input
Rate
Target Range
CO
2
O
2
CO
2
O
2
High Fire
10.8% 4.5% 10.5% - 11.5% 3.5% - 5.0%
Low Fire
10.5% 5.0% 10.0% - 11.0% 4.2% - 5.8%
CO levels should be less than 200 ppm.
Combustion Analysis Procedure
1. Turn the main power off to the boiler by placing the “On/
Off” switch in the OFF position.
2. Remove the combustion plug from the vent connector
provided on the unit. Insert the probe from a combustion
analyzer into the opening on the vent connector. Note:
Combustion measurements will be made at this point.
3. Turn the main power on to the boiler by placing the “On/
Off” switch in the ON position. Place the boiler into the
active position by pressing the RIGHT SELECT [ON]
key (see the Knight Fire Tube Boiler Display in Section 1
of this manual). Note: The brackets ([]) denote screen
status.
4. Locate the pinhole button above the RESET button on
the display board. Insert a thin wire (such as a paper
clip) into the hole and press the button once and hold for
5 seconds to place the boiler into Service Mode.
NOTE: In Service Mode, the boiler will fire at normal
ignition speed and will then modulate up to full fire. You
can switch between high fire and low fire by pressing the
Right Arrow Key (>).
5. Once the boiler has modulated up to full fire, measure the
combustion. The values should be in the range listed in
Table 3-5. The CO levels should be less than 200 ppm for
a properly installed unit.
If the combustion is not within the specified range,
reference the Troubleshooting Section of this manual for
possible causes and corrective actions.
6. Once the combustion analysis is complete, re-install the
plug in the vent connector.
Test the safety shutoff device by switching the manual
shutoff switch to the OFF position and ensuring that the
boiler shuts down and registers an alarm. Turn the
manual shutoff switch to the ON position and reset the
control. Place the boiler back into normal operation.
⚠
WARNING