LAARS Mighty Therm AP (Sizes 2000-5000) - Installation, Operation and Maintenance Instructions - Manual (Page 6)

Page 6
LAARS Heating Systems
4. Liquified petroleum is heavier than air.
Therefore, the pool boiler should not be installed
in pits or other locations where gas could
accumulate. The boiler should be located a safe
distance from LP gas storage and filling
equipment. Consult local codes and fire
protection authorities for advice relative to
specific installation restrictions.
2D. Freeze Protection
Boiler installations are not recommended in areas
where the danger of freezing exists unless proper
precautions are made for freeze protection.
2E. Gas Supply and Piping
Review the following instructions before
proceeding with the installation.
1. Verify that the boiler is fitted for the proper type
of gas by checking the rating plate. Laars boilers
are normally equipped to operate below a 2000
foot altitude. Boilers equipped to operate at
higher altitudes have appropriate stickers or tags
attached.
2. Use the figures in Table 3 to provide adequate
gas piping (check local code for BTU capacity
required).
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 Propane
Min. (inches water column) 7 11
Max. (inches water column) 9 14
Note: The boiler and all other gas appliances
sharing the 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 conforms 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.
Distance from Gas Meter or
Natural and LP Gas
0-100' 100-200' 200-300'
Indoor Outdoor
Size Size Nat. LP Nat. LP Nat. LP
2000 — 2½ 2 3 2½ 3 3
2450 2200 3 2½ 3 2½ 3½ 3
3050 2800 3 2½ 3½ 3 3½ 3
3500 3200 3 2½ 3½ 3 4 3½
4050 3600 3½ 3 4 3½ 4 3½
4500 4000 3½ 3 4 3½ 5 4
5000 4500 4 3½ 4 3½ 5 4
NOTES:
These figures are based on ½" water column pressure drop.
Check supply pressure and local code requirements before
proceeding with work.
Pipe fittings must be considered when determining gas pipe
sizing.
3. A trap (drip leg) must be provided ahead of the
gas controls (see Figure 5). Where required by
code, provide a second manual gas shutoff valve.
Do not remove manual valve furnished with the
unit.
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
Figure 5. Tee Fitting Sediment Trap.