Combustion Analysis Procedure - Crest Audio FBN0751 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 fitting from the flue collector. 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. Navigate to the Service Screen from the Home Screen
by pressing the MAIN MENU button and then the
SERVICE button.
5. On the Service Screen place heater into Service Mode
by selecting the START button, then selecting Set Gas
Valve 1 - High.
6. Insert the probe from a combustion analyzer into the
hole left by the removal of the fitting.
7. Once the boiler has modulated up to rate, measure
the combustion. The values should be in the range
listed in Table 3I. CO levels should be less than 200
ppm for a properly installed unit. If the combustion is
not within range reference the Troubleshooting Chart
below for possible causes and corrective actions.
Table 3H Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
Vent/Air Intake Length
or Obstruction
Gas Supply Pressure
Dirty/Damaged Burner
Gas Valve Adjustment
52
• Refer to Section 2 - General Venting of the Crest Installation and Operation Manual
for the proper venting and air intake methods for the Crest boiler.
• Check for obstructions at the vent/air intake terminals.
• Refer to Section 6 - Gas Connections of the Crest Installation and Operation
Manual for the proper gas supply for the Crest boiler.
• Refer to page 34 of this manual for burner removal and cleaning procedures.
• Replace burner if necessary.
• Refer to page 53 of this manual for the gas valve adjustment procedure.
Table 3I Flue Products
Natural Gas
Flue Products
Gas Valve
CO 2 (%)
Valve 1 High 9.5
Valve 1 Low 9.0
Valve 2 High 9.5
Valve 2 Low 9.0
Propane
Valve 1 High 11.0
Valve 1 Low 10.2
Valve 2 High 11.2
Valve 2 Low 10.5
**All set points should be within +/- 0.2%**
8. After Gas Valve 1 is set, repeat the same procedure for the
second gas train by selecting Set Gas Valve 2 - High on the
Service Screen.
9. Once the heater analysis is complete, test the safety shutoff
device by turning the manual shutoff valve to the OFF
position and ensuring that the heater shuts down and
registers an alarm. Open the manual shutoff valve and reset
the control.
10. Turn the main power off to the boiler and replace the
fitting into the flue pipe connection.
11. Place the boiler back into normal operation.
You must replace the fitting to prevent
WARNING
flue gas spillage into the room. Failure
to comply could result in severe personal
injury, death, or substantial property
damage.
CORRECTIVE ACTION
Service Manual
O 2 (%)
4.0
4.9
4.0
4.9
4.1
5.3
3.8
4.9