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LAARS HEATING SYSTEMS
2D. Freeze Protection
Although Mighty Max VW heaters are design-
certified by International Approval Services (IAS)
(formerly AGA CGA) for outdoor installations, such
installations are not recommended in areas subject to
freezing temperatures unless proper precautions are
taken. Consult the local factory representative or
Laars for additional information.
2E. Installation of Indoor Water Heaters
Combustion Air Supply and Ventilation:
There are a variety of options available to the
installer when it comes to venting and combustion air;
venting can be vertical or horizontal, it can originate
at the top of the heater or the back, and combustion air
can be obtained from the room where the heater is
installed or ducted directly to the heater from outdoors
(see Sections 2H through 2K for details).
2F. Gas Supply and Piping
Review the following instructions before
continuing the installation.
1.
Gas piping installation must be in accordance
with the latest edition of ANSI Z223.1/NFPA 54.
In Canada, the installation must be in accordance
with CAN1-B149.1 or .2 and all local codes that
apply (see Figure 3 for heater gas valve
arrangement).
2.
Check the rating plate to make sure the heater is
fitted for the type of gas being used. Laars
heaters are normally equipped to operate below a
2000 foot (610m) altitude. Heaters equipped to
operate at high altitudes have appropriate
stickers or tags attached.
3.
The figures in Table 3 should be used to size the
gas piping from the gas meter to the heater.
Check local codes for BTU/h capacity required.
4.
Install a sediment trap (drip leg) ahead of the gas
controls (see Figure 4). Fit the trap with a
threaded cap which can be removed for cleaning.
5.
When required by code, install a second manual
gas shutoff valve. Do not remove manual shutoff
valve supplied with the heater.
6.
Disconnect the heater and its individual shutoff
valve from the gas supply piping system during
pressure testing of the system at pressures higher
than 1/2 psi (3.5 kPa). Isolate the heater 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 psi
(3.5 kPa).
7.
Gas supply pressures to the heater are listed in
Table 4.
NOTE: The heater and all other gas appliances
sharing the heater 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 undersize gas meter and/or obstructed
gas supply line.
Supply Pressure
Natural Gas
Propane Gas
Water Column
in.
mm
in.
mm
Minimum
5
127
9
229
Maximum
9
229
14
356
Table 4. Gas Supply Pressure Requirements.
8.
Do not exceed the maximum inlet gas pressures
specified. Excessive pressure will result in
damage to the heater's gas controls. The
minimum pressures specified are for gas input
adjustment.
9.
The correct differential gas pressure is stamped
on the rating plate. The regulator is preset at the
factory, but may need adjustment for altitude per
Section 3.
10.
Before operating the heater, test the complete
gas supply system and all connections for leaks
using a soap solution.
Caution
Since some leak test solutions (including soap and
water) may cause corrosion or stress cracking, rinse
the piping with water after testing.
Figure 4. T-Fitting Sediment Trap Installation.
Gas Supply
Inlet
Tee
Fitting
3 in.
(76mm) Min.
Cap
Nipple
To Equipment
Inlet
Summary of Contents for Mighty Max VW Series
Page 25: ...Mighty Max Volume Water Heater Page 25 Figure 19 Troubleshooting Chart...
Page 27: ...Mighty Max Volume Water Heater Page 27 Front View Right Side View...
Page 28: ...Page 28 LAARS HEATING SYSTEMS Front View Rear View Right Side View Left Side View...
