LAARS Mighty Therm PH (Sizes 500-1825) - Installation, Operation and Maintenance Instructions - Manual (Page 10)

LAARS Heating Systems
Page 10
shutoff valve must also be provided for service
convenience and safety. Check the local codes.
4. The boiler and its individual shutoff valve must
be disconnected from the gas supply piping
system during any pressure testing of that system
at test pressures in excess of 1/2 psig. The boiler
must be isolated from the gas supply piping
system by closing its individual manual gas
shutoff valve during any pressure testing of the
gas supply piping system at test pressures equal
to or less than 1/2 psig.
5. Provide gas supply pressure to the boiler as
follows:
Natural Gas LPG
Min. (inches
Per Rating Plate
water column)
Max. (inches
9 14
water column)
Note: The boiler and all other gas appliances
sharing the boiler gas supply line must be firing at
maximum capacity to properly measure the inlet
supply pressure. Low gas pressure could be an
indication of an undersized gas meter and/or
obstructed gas supply line.
6. The correct burner manifold gas pressure is
stamped on the rating plate. The regulator is
preset at the factory and normally requires no
further adjustment.
7. The gas manifold and control assembly was
tested and conform to the safe lighting and other
performance criteria specified in the latest
editions of ANSI Z21.13 and CGA 3.3 Low
Pressure Boiler Standard.
8. Before operating the boiler, the complete gas
supply system and all connections must be tested
for leaks using a soap solution. Do not use raw
flame.
Caution
Since some leak test solutions (including soap
and water) may cause corrosion or stress
cracking, the piping must be rinsed with water
after testing, unless it has been determined
that the leak test solution is noncorrosive.
2E. Electrical Wiring
Electrical diagrams are included with the packet
provided with each unit.
WARNING
The boiler must be electrically grounded in
accordance with the most recent edition of the
National Electrical Code, ANSI/NFPA 70. In
Canada, all electrical wiring to the boiler should
be in accordance with the Canadian Electrical
Code, CSA C22.1 Part 1. Do not rely on the
gas or water piping to ground the metal parts
of the heater. Frequently, 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
underground boiler.
1. Check boiler wiring and pump for correct
voltage, frequency and phase. If the pump circuit
is other than 115V, check to see that the boiler is
provided with an appropriate transformer.
2. Wire the boiler and pump exactly as shown in
the wiring diagram supplied with the boiler.
Table 4. Gas Piping Sizes.
Distance from Gas Meter
or Last Stage Regulator
Size 0-100' 100-200' 200-300'
(0-30.5m) (30.5-61m) (61-91.4m)
500
600
715
850
1010
1200
1430
1670
1825
1-1/2"
1-1/2"
2"
2"
2"
2-1/2"
2-1/2"
2-1/2"
2-1/2"
2"
2"
2"
2-1/2"
2-1/2"
3"
3"
3"
3"
2"
2-1/2"
2-1/2"
2-1/2"
3"
3"
3"
3"
3-1/2"
Note: These figures are for Natural Gas (.65 Sp. Gr.), and are
based on 1/2" water column pressure drop. Check supply
pressure with a manometer, and local code requirements for
variations. For LPG, reduce pipe diameter one size, but maintain
a 1" minimum diameter. A normal number of Tees and elbows
have been taken into allowance.
Figure 11. T-Fitting Sediment Trap Installation.