LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 55)

Page 51 N eo T herm Boilers and Water heaters
3. Observe all warnings on the Operating Instructions
label and turn on the gas and electrical power to the
appliance.
4. The NeoTherm unit will begin the start sequence.
The blower and pump will energize for the pre-purge
period, then the ignition sequence will start. After all
safety devices have been verified, the gas valve will
open. If ignition doesn’t occur, turn off the NeoTherm,
and check that there is proper gas supply. Wait 5
minutes before restarting.
5. Turn the NeoTherm on.
6. After placing the appliance in operation, the Burner
Safety Shutoff Device must be tested:
• Close the gas shutoff valve with the burner operating.
• The flame will go out and the blower will
continue to run for the post purge cycle. One
or three additional attempts to light will follow.
Each cycle will include pre-purge, ignitor on,
valve/flame on, and post purge. Ignition will not
occur because the gas is off. The ignition control
will lockout.
• Open the gas shutoff valve. Reset the boiler
control by pressing the Reset button on the
control or on the display. Restart the appliance.
The ignition sequence will start again and the
burner will start. The appliance will return to its
previous mode of operation.
DANGER
If you detect any odor of gas, or if the gas burner
does not appear to be functioning in a normal
manner, CLOSE THE MAIN SHUTOFF VALVE.
Do not shut off the switch. Contact your heating
contractor, gas company, or factory representative.
9.3 Adjusting CO
2
1. Measure the CO
2
/O
2
in the flue products at high fire.
The NeoTherm can be forced to high fire to allow for
easier setup. The controller has a feature that makes it
easy to go directly to the high fire condition. The unit
will operate at high fire for 5 minutes, then modulate
down automatically.
How to get there: From the “Home” screen,
press “I” to go to “Info/ Install.” Choose “Test,” then
go to “Forced Rate.” Select “Set High Fire,” then
select “Start Test.”
The CO
2
readings should be between the values shown
in Table 15 R or Table 15 C. If the CO
2
is not within
the range shown, adjustments may be made. To adjust
the high fire CO
2
, locate the high fire adjuster screw
according to the appropriate figure. Slowly make
adjustments in 1/16 of a revolution increments until the
CO
2
is within the range identified.
2. Measure the CO
2
/O
2
in the flue products at low fire.
3. Repeat steps 1 and 2 to confirm that the CO
2
ranges are
within the required ranges. Adjust if necessary.
4. Confirm that the differential pressure is still within the
appropriate range.
5. If any of the measurements cannot be adjusted to the
specified ranges or the CO levels are above 150ppm
when adjusted, please consult the factory for further
information.
WARNING
Improper adjustment may lead to poor combustion
quality, increasing the amount of carbon monoxide
produced. Excessive carbon monoxide levels may
lead to personal injury or death.
Table 15 C (Commercial, sizes 399 - 850 Mbtu)
CO
2
Range and Manifold Pressure
GAS TYPE HIGH FIRE, CO
2
LOW FIRE, CO
2
DIFFRNTL PRESSURE
( inches wc)
Natural 8.8 to 9.8% 0.5% lower than
3.6” to 3.9”
Propane 9.8 to 10.2% high fire setting
Table 15 R (Residential, sizes 80 - 285 Mbtu)
CO
2
Range and Differential Pressure
NeoTherm can be forced to low fire to allow for easier
setup.
How to get there: From the “Home” screen, press
“I” to go to “Info/ Install.” Choose “Test,” then go
to “Forced Rate.” Select “Set High Fire,” then select
“Start Test.”
The CO
2
readings should be between the values shown
in Tables 15 R or Table 15 C. If the CO
2
is not within
the range shown, adjustments may be made. To adjust
the low fire CO
2
, locate the low fire adjuster screw
according to the appropriate figure. Slowly make
adjustments in 1/16 of a revolution increments until the
CO
2
is within the range identified.
GAS TYPE HIGH FIRE, CO
2
LOW FIRE, CO
2
MANIFOLD
PRESSURE
Natural 8.8 to 9.0% 0.5% lower than -.005” to
Propane 9.8 to 10.0%
high fire setting -.015” wc