86
Combustion Analysis Procedure
1. Turn the main power off to the boiler.
2. Hold
the
►
plus the
▼
button for five (5) seconds to
enter Service Mode.
3. Once the boiler has modulated up to full fire, measure the
combustion. Place the analyzer probe in the fitting on
the flue adapter. The values should be in the range listed
in Table 13-5. The CO levels should be less than 150 ppm
for a properly installed unit.
If the combustion is not within the specified range,
reference Table 13-6 for possible causes and corrective
actions.
Table 13-6 Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
CORRECTIVE ACTION
Vent/Air Intake Length
or Obstruction
• Refer to Section 3 - General Venting for the proper venting and air intake methods for the
Noble Combi Boiler.
• Check for obstructions at the vent/air intake terminals.
Gas Supply Pressure
• Refer to Section 7 - Gas Connections for the proper gas supply for the Lochinvar Combi
Boiler.
Dirty/Damaged Burner
• Refer to page 72 of this manual for burner removal.
• Replace burner if necessary.
Gas Valve Adjustment
• Refer to this page of the manual for the gas valve adjustment procedure.
13
Troubleshooting
Table 13-5 Flue Products
You must replace the cap on the vent
adapter 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 adjustment procedure
4. Once the combustion analysis is complete, test the safety
shutoff device by turning the manual shutoff switch to
the OFF position and ensuring that the boiler shuts
down and registers an alarm. Turn the manual gas valve
to the ON position and reset the control.
5. Turn the main power off to the boiler and replace the cap
on the sample port.
6. Place the boiler back into normal operation.
If adjustment of the gas valve is deemed necessary, use the
following procedure:
CAUTION
Under normal operating conditions this
valve should not need adjusting.
Locate the throttle adjustment screw on the top of the gas
valve, see FIG. 13-2. Using a 2.5 mm Allen wrench, turn
the screw 1/8 turn
counterclockwise
to increase CO
2
levels
or 1/8 turn
clockwise
to decrease CO
2
levels. After one
adjustment on the valve, follow the Combustion Analysis
to measure the combustion.
If combustion is still not within the specified range,
repeat the procedure. This procedure SHOULD NOT
be performed more than four (4) times. If after four (4)
adjustments and the combustion is still not within the
specified range, revisit the possible causes in Table 13-6
(this page) or replace the gas valve.
A
DETAIL A
DIR #2000534505 00
THROTTLE
ADJUSTMENT
SCREW
THROTTLE
ADJUSTMENT
SCREW
Figure 13-2 Gas Valve Adjustment
Installation & Service Manual
Goal
Natural Gas
Propane
CO
2
O
2
CO
2
O
2
Range
8.5% - 10.5% 2.3% - 5.7% 10.0% - 11% 4.1% - 5.6%
Target
9.0% 4.9% 10.5%
4.9%
F I R E T U B E C O M B I
™
