Combustion Analysis Procedure - Lochinvar 50 Service Manual

3
Troubleshooting

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 flue temperature sensor from the flue pipe
connection. 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.
4. Place the boiler into the active position by pressing the
ENTER/RESET button on the display board (see page 7)
until BLR:Standby appears in the display window.
5. Locate the pinhole button above the "T" in the Knight
logo on the display board (see page 7). Press the button
once and hold for 5 seconds to place the boiler into
Service Mode. In Service Mode the boiler will fire at
ignition speed and will then modulate up to full fire.
6. Insert the probe from a combustion analyzer into the hole
left by the removal of the flue temperature sensor.
7. Once the boiler has modulated up to full fire, measure the
combustion. The values should be in the range listed in
Table 3H above. The CO levels should be less than
150 ppm for a properly installed unit.
If the combustion is not within the specified range,
reference the chart below for possible causes and
corrective actions.
Table 3G Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
Vent/Air Intake Length
or Obstruction
Gas Supply Pressure
Dirty/Damaged Burner
Gas Valve Adjustment
40
• Refer to Section 3 - General Venting of the Knight Wall Mount Installation and Operation
Manual for the proper venting and air intake methods for the Knight wall mount boiler.
• Check for obstructions at the vent/air intake terminals.
• Refer to Section 7 - Gas Connections of the Knight Wall Mount Installation and Operation
Manual for the proper gas supply for the Knight wall mount boiler.
• Refer to page 26 of this manual for burner removal and cleaning procedures.
• Replace burner if necessary.
• Refer to page 41 of this manual for the gas valve adjustment procedure.
Table 3H Flue Products
Natural Gas
CO O
2
8.0% - 10% 3.0% - 6.5%
8. Once the combustion analysis is complete, test the safety
shutoff device by turning the manual shutoff valve to the
OFF position and ensuring that the boiler shuts down
and registers an alarm. Open the manual shutoff valve,
reset the control, and return to Service Mode.
9. Turn the main power off to the boiler and replace the flue
temperature sensor into the flue pipe connection.
10. Place the boiler back into normal operation.
You must replace the flue gas temperature
WARNING
sensor to prevent flue gas spillage into the
room. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
CORRECTIVE ACTION
Service Manual
Propane
CO
2 2
9.0% - 11% 4.1% - 6.9%
O
2