LAARS Mighty Therm LO-NOx PW (Sizes 500-1825) - Install and Operating Manual - Manual (Page 18)

LAARS HEATING SYSTEMS Page 18
4. Do not use this appliance if any part has been
under water. Immediately call a qualified service
technician to inspect the appliance and to replace
the heater.
4.5.1 Lighting Instructions
1. STOP! Read the safety information (1 through 4)
above.
2. Turn off all electric power to the appliance.
3. Remove control access panel.
4. Set the thermostat or aquastat to lowest setting.
5. This appliance is equipped with an ignition
device which automatically lights the burner. Do
not try to light the burner by hand.
6. Turn off manual gas valve. Valve is off when
valve handle is at right angle to the gas pipe. On
combination valves (size 500 and 715) turn gas
control knob clockwise
to OFF position (see
Figure 19).
7. Wait five (5) minutes to clear out any gas. Then
smell for gas, including near the floor. If you
smell gas, STOP! Follow the safety information
titled “Before Operating”. If you don't smell gas,
go to next step.
8. Turn gas control knob counterclockwise
to ON.
9. Set thermostat or aquastat to desired setting.
10. Replace control access panel.
11. Turn on all electric power to the appliance.
12. If the appliance will not operate, follow the
instructions “To Turn Off Gas To Appliance”
and call your service technician or gas supplier.
4.5.2 To Turn Off Gas to Appliance
1. Turn off all electric power to the appliance if
service is to be performed.
2. Remove control access panel.
3. Set the thermostat or aquastat to lowest setting.
4. Turn the gas control knob clockwise to OFF.
Do not force.
5. Replace control access panel.
4.6 Setting the Temperature Controls
4.6.1 Hydronic Boilers
To set the temperature and high-limit controls:
1. Set the temperature controller at the system
design temperature.
2. Set the high-limit 40°F to 50°F above
temperature controller setting.
4.6.2 Water Heaters
The hi-limit switch is factory set and should not
be adjusted.
WARNING
Adjusting the temperature control past the
recommended setting can result in a scalding
injury. Hot water can produce third degree
burns in 6 seconds at 140°F (60°C) and in 30
seconds at 130°F (54°C).
Water temperature can be adjusted at the
temperature control. The temperature control is
adjusted to its lowest setting when it is shipped from
the factory. The 130°F (54°C) setting is the
recommended starting point for setting the
temperature control. Make sure that the hi-limit switch
is set 30°F (17°C) higher than the temperature control.
The recommended setting will result in
satisfactory energy savings. Lowering the temperature
may result in reduced energy costs. Connecting the
heater to a separate storage vessel and lowering the
temperature setting, may reduce energy losses during
standby periods when hot water is not being used, and
may meet normal hot water needs. For increased hot
water usage, a higher temperature setting may be
necessary to meet increased demand. Reset the
temperature setting to a lower level after periods of
increased usage are over.
SECTION 5.
Maintenance
Caution
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
5.1 General Instructions
1. Oil the water circulating pump in accordance
with the manufacturer's instructions.
2. Oil the combustion air blower motor bearings
every 6 months.
3. If a strainer is used in a pressure reducing valve
or in the piping, clean it every 6 months in
accordance with the manufacturer's instructions.