LAARS Mighty Therm HH-PH (Sizes 175-400) - Installation, Operation and Maintenance Instructions - Manual (Page 19)

Mighty Therm HH-PH Hydronic Boilers Page 19
Consult local codes and fire protection authorities
about specific installation restrictions.
2H. Electrical Wiring
WARNING
Electrically ground the boiler in accordance with the
latest edition of the National Electrical Code, ANSI/
NFPA 70. In Canada, use C22.1. Do not rely on the
gas or water piping to ground the metal parts of the
boiler. Often, plastic pipe or dielectric unions isolate
the boiler electrically. Service and maintenance
personnel who work on or around the boiler may be
standing on wet floors and could be electrocuted by
an ungrounded boiler.
1. Check boiler wiring and pump for correct
voltage, frequency, and phase. If the pump
circuit is other than 120V AC, check to make
sure the boiler is provided with an appropriate
transformer.
2. Wire the boiler and pump exactly as shown on
the wiring diagram found on the inside of the
boiler. See Figures 28 and 29 for typical
examples of the wiring diagram.
3. Electrically interlock the pump and boiler so the
boiler cannot come on unless the pump is
running.
4. Connect all field-installed devices (draft
switches, relays, timers, outdoor temperature
reset devices, etc.) (see Figures 28 and 29) to the
boiler wiring at points labeled Field Interlock.
SECTION 3.
Operating Instructions
NOTE: Safe lighting and other performance
criteria were met with the gas manifold and control
assembly installed on the boiler during tests specified
in ANSI Z21.13.
Figure 30. Temperature Controls.
WARNING
For your safety, when starting the boiler, keep your
head and face well away from the lower firebox
opening to prevent any risk of personal injury.
Vent pipes, drafthoods, and boiler tops get hot!
These surfaces can cause serious burns. Do not
touch these surfaces while the boiler is in operation.
Adding a vent cap reduces the temperature on the
top.
PROPANE GAS: To avoid possible injury, fire and
explosion, read and follow these precautions and all
instructions on this boiler before lighting the pilot.
This boiler uses propane gas which is heavier than
air and will remain at ground level if there is a leak.
Before lighting, sniff at ground level.
If you smell gas, follow these rules:
1. DO NOT light matches. DO NOT turn electric
lights or switches on or off in area. DO NOT use
an electric fan to remove the gas from area.
2. Shut off gas at propane tank.
3. Telephone gas company and fire department for
instructions. Give your name, address and phone
number.
If your propane tank runs out of fuel, turn off gas at
the boiler. After the tank is refilled, the boiler must
be relit in accordance with the instructions found on
the inside of the boiler. DO NOT attempt repairs on
the gas control or boiler. Tampering is dangerous
and voids all warranties.
3A. Setting the Temperature Controls
Boilers are shipped with the temperature control
sensor bulb located in the inlet side and the hi-limit
switch sensing bulb is in the outlet side (see Figure
18). Set the temperature control (see Figure 30) at the
designed system supply temperature less the
TEMPERATURE CONTROLLER
MANUAL RESET HI-LIMIT