LAARS Mighty Therm VW-PW (Sizes 175-400) - Installation, Operation and Maintenance Instructions - Manual (Page 4)

LAARS Heating Systems
Page 4
number for the drafthood is on the heater rating plate.
Follow this procedure to make the conversion:
a. Remove the top filler plate, stamped “HOT”, by
slipping a fine-blade screwdriver into the slot at
the rear of the plate and gently prying it up (see
Figure 2).
b. Remove the two screws attaching the adapter
plate to the top assembly and lift it out (see
Figure 3).
c. Remove the vent cap or drafthood from its
package.
SECTION 2.
Installation Instructions
2.1 General Information
WARNING
Follow local regulations with respect to installation of
carbon monoxide (CO) detectors and
manufacturer's maintenance schedule of the heater.
Install the VW-PW heaters in accordance with
the procedures in this manual (or the Laars warranty
may be voided), local codes and ordinances. In the
absence of such codes, install the heaters in
accordance with the latest edition of the National Fuel
Gas Code, ANSI Z223.1. In Canada, the installation
must be in accordance with CAN1-B149.1 or .2 and
local codes. The authority having jurisdiction may
require the installation conform to the Standard for
Controls and Safety Devices for Automatically Fired
Heaters, ANSI/ASME CSD-1. Any changes to the
heater, gas controls, gas orifices, wiring or draft
diverter may void the warranty. If field conditions
require a change to any of the above, consult the
factory.
All gas-fired products require correct installation
to assure safe operation. The requirements for heaters
include the following:
1. Field assembly of drafthood or vent cap (see
Section 2B).
2. Appropriate site location (clearances) and
flooring.
3. Sufficient combustion and ventilation air.
4. Adequate venting of combustion products.
5. Adequate water flow.
6. Properly sized gas meter and piping.
7. Proper electrical wiring.
This manual provides the information needed to
meet these requirements. Review all application and
installation procedures completely before continuing
the installation.
2.2 Field Assembly
The VW-PW heater is shipped from the factory
with the top assembly in the low-profile configuration
for outdoor installations.
The VW-PW heater is design certified for indoor
installation when equipped with a special drafthood,
which must be installed without modification. The part
Figure 2. Top filler plate. Figure 3. Adapter plate.
Figure 4. Flue transition Figure 5. Vent cap with
ring. adapter plate
(outdoor).
Figure 6. Drafthood with Figure 7. Drafthood switch
adapter plate receptacle.
(indoor).