LAARS Mighty Therm2 MT2V (Sizes 200, 300, 400) - Install and Operating Manual - Manual (Page 29)

Mighty Therm 2
(200, 300, 400) Page 29
blower off.
6.6 Operating the Burner and Set-Up
6.6.1 Set-Up for 0 to 2500 Feet Altitude
The setup must be checked before the unit is
put in operation. Problems such as failure to start,
rough ignition, strong exhaust odors, etc. can be due
to improper setup. Damage to the Mighty Therm2
resulting from improper setup is not covered by the
limited warranty.
1. Using this manual, make sure the installation
is complete and fully in compliance with the
instructions.
2. Determine that the appliance and system are
filled with water and all air has been bled from
both. Open all valves.
3. Observe all warnings on the Operating
Instructions label and turn on gas and electrical
power to appliance.
4. Switch on the appliance power switch located on
the right side of the unit.
5. The Mighty Therm2 will enter the start sequence,
as long as the unit is being called for heat. The
blower and pump come on for pre-purge, then
the ignitor warm-up sequence starts and after
the ignitor warm-up is complete and all safety
devices are verified, the gas valves open. If
ignition doesn’t occur, check that there is proper
gas supply. Wait 5 minutes and start the unit
again. During initial start up, air in the gas line
may cause the Mighty Therm2 to "lock out"
during the first few trials for ignition. If the
ignition control locks out, reset by cycling the
power off and on using the main power switch on
the right side of the cabinet.
6. When the unit is running, the supply gas pressure
must be checked. Inlet gas pressure must not
exceed 13 in. w.c. (3.2 kPa). The minimum inlet
gas pressure is 5 in. w.c. (1.2 kPa) and 8 in. w.c.
(2 kPa) for LP.
7. Once the inlet gas pressure is verified, the
outlet gas pressure from each valve (manifold
gas pressure) must be checked, and adjusted, if
necessary. The manifold gas pressure must be 3.0
in. w.c. (0.62 kPa) for natural gas and 9.0 in. w.c.
(2.2 kPa) for LP.
8. Complete the setup by checking the CO
2
at the
outlet of the unit. The CO
2
should be 8% for
natural gas, or 9.2% for LP.
9. After placing the appliance in operation, the
Burner Safety Shutoff Device must be tested.
To test:
(a) Close gas shutoff valve with burner
operating.
(b) The flame will go out and blower will
continue to run for the post purge cycle.
Three attempts to light will follow. Ignition
will not occur as the gas is off. The ignition
control will lockout, and will have to be
reset by cycling the power before the unit
will operate.
(c) Open gas shutoff valve. Restart the
appliance. The ignition sequence will
start again and the burner will start. The
appliance will return to its previous mode
of operation.
10. Check all heat exchanger water connections,
flange and header gaskets for watertight integrity
24 hours after commissioning. If there are any
signs of water leakage, re-torque fasteners or
re-seat threaded connections as necessary to
eliminate leakage.
6.6.2 High Altitude Adjustment and
Set-Up
High altitude adjustment must not be made on
appliances operating at elevations below 2500 ft. (762 m).
No orifice changes are required to adjust the
Mighty Therm2 appliances for high altitude. High
altitude adjustment is accomplished by adjustment
of the air shutter. A CO
2
or O
2
analyzer is required to
make these adjustments.
Start the adjustment process by checking the CO
2
in the “as installed” condition. Adjust the air shutter(s)
so that the CO
2
is about 8% or the O
2
is about 6.8%
for appliances operating on natural gas. For appliances
operating on LP Gas adjust the air shutter(s) so that the
CO
2
is about 9.2% or the O
2
is about 6.8%.
If the appropriate CO
2
/ O
2
levels cannot be
achieved by adjusting the air shutter. Contact the
Technical Services Department at number shown on
back page.
The amount of derate will vary depending on
heating value of the fuel and the elevation at the
installation site.
Caution
Should any odor of gas be detected, or if the
gas burner does not appear to be functioning
in a normal manner, close main shutoff valve,
do not shut off switch, and contact your heating
contractor, gas company, or factory representative.
Attention
Si vous sentez une odeur de gaz ou si le brûleur
à gaz ne parait pas fonctionner de manière
normale, fermez la vanne d’isolement, ne fermez
aucun interrupteur, et appelez votre entreprise
de chauffage, la compagnie de gaz ou un
représentant du fabricant.