LAARS Mighty Therm LO-NOx PW (Sizes 500-1825) - Install and Operating Manual - Manual (Page 17)

Mighty Therm Lo-NOx Page 17
NOTE: Safe lighting and other performance
criteria were met with the gas manifold and control
assembly provided on the heater when it underwent
tests specified in ANSI Z21.13 and CAN1-4.3-M85.
Before placing the heater in operation, check the
automatic safety shutoff devices. Once the heater is
connected to the gas piping and after all of the
requirements in Sections 2 and 3 have been met,
follow these procedures:
1. Before beginning the tests, make sure the main
manual gas valve, and any other heater firing
valves, are in the OFF position. The heater's gas
valve is turned OFF as follows:
a. Sizes 500 and 715: Turn the gas control
knob clockwise to OFF.
b. Sizes 1010 through 1825: Manual gas valve
is OFF when handle is at right angle to the
gas pipe (see Figure 19).
2. The ignition control turns on the combustion
blower. After about a 15 second pre-ignition
purge, while the blower clears the combustion
chamber, the igniter is turned on. The igniter
takes about 25 seconds to heat up. A glow can be
seen through the view port (see Figure 17).
3. The manual gas valve must be ON for the burner
to ignite. This valve is turned ON as follows:
a. Size 500 and 715: Turn counterclockwise
to ON (see Figure 19).
b. Sizes 1010 through 1825: Valve is ON
when handle is parallel to the gas pipe (see
Figure 19).
4.4 Hi-Limit Checkout
After running the boiler for a long enough period
to bring the water temperature within the range of the
hi-limit, slowly back off the high limit setting until the
boiler shuts off. The main burners should re-ignite
when the hi-limit is turned back up to its original
setting and the hi-limit is reset.
4.5 Start-Up Procedure
(See Section 4.2 for Startup
Requirements)
WARNING
If you do not follow these instructions exactly, a
fire or explosion may result causing property
damage, personal injury or loss of life.
1. This appliance does not have a pilot. It is
equipped with an ignition device which
automatically lights the burner. Do not try to
light the burner by hand.
2. BEFORE OPERATING, smell all around the
appliance area for gas. Be sure to smell next to
the floor because some gas is heavier than air
and will settle to the floor.
WHAT TO DO IF YOU SMELL GAS
a.
Do not try to light any appliance.
b. Do not touch any electric switch; do not
use any phone in your building.
c. Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.
d. If you cannot reach your gas supplier, call
the fire department.
3. Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will
not push in or turn by hand, don't try to repair it,
call a qualified service technician. Force or
attempted repair may result in a fire or
explosion.
Figure 19. Handle Position of Gas Valves.
2. Before placing the heater in operation, be certain
that the heater is filled with water and all air is
purged from the system.
3. Make sure the power switch on the heater is in
the ON position. Reset all safety devices (hi-
limit, switch, low water cutoff, etc.).
4.3 Normal Operating Sequence
When the circulation pump is running, the heater
will turn itself on and off via the temperature control.
When the water temperature drops below the
differential setting, below the set point, the following
sequence happens:
1. The temperature control (aquastat) powers the
ignition control.