3
Troubleshooting
Service Manual
52
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 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 flue
temperature sensor.
7. Once the heat exchanger 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
CORRECTIVE ACTION
Vent/Air Intake Length
or Obstruction
• 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.
Gas Supply Pressure
• Refer to Section 6 - Gas Connections of the Crest Installation and Operation
Manual for the proper gas supply for the Crest boiler.
Dirty/Damaged Burner
• Refer to page 34 of this manual for burner removal and cleaning procedures.
• Replace burner if necessary.
Gas Valve Adjustment
• Refer to page 53 of this manual for the gas valve adjustment procedure.
Table 3I Flue Products
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
flue temperature sensor into the flue pipe connection.
11. Place the boiler back into normal operation.
You must replace the flue gas temperature sensor
to prevent flue gas spillage into the room. Failure
to comply could result in severe personal injury,
death, or substantial property damage.
WARNING
Gas
Valve
Natural Gas
Propane
CO
2
O
2
CO
2
O
2
1 - High 3.5% - 5.5% 11.2% - 14.8% 5.1% - 6.8% 10.5% - 13.2%
2 - High 7.8% - 8.6% 5.6% - 7.1% 9.4% - 11.0% 4.1% - 6.6%
Summary of Contents for Crest 1.5
Page 54: ...3 Troubleshooting 54 NOTES ...
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