Install Instructions

1 Determine unit location (continued)
11
TABLE 1A
COMBUSTIBLE FLOOR KITS
Model Kit Number
497 100136977
647 100136978
747 100136979
⚠ CAUTION
Although these units are CSA International design-
certi ed for outdoor installations, such installations are not
recommended in areas where the danger of f reezing exists. You must
provide proper freeze protection for outdoor installations, units
installed in unheated mechanical rooms or where temperatures
may drop to the freezing point or lower. If freeze protection is
not provided for the system, a low ambient temperature alarm is
recommended for the mechanical room. Damage to the unit by
freezing is non-warrantable.
Anytime the temperature measured at any of the sensors
(except the outside air temperature sensor) drops below 40°F, the
control turns on the pump contact and the alarm relay.  e
pump will shut o when both sensors are above 50°F.
Freeze protection
 is unit is equipped with a pump delay of 30 seconds. If
continuous operation of the pump is desired, the pump must
be electrically connected to another circuit. Connection of
the pump to this unit will provide intermittent pump delay
operation.
Pump operation
Locate indoor boilers and water heaters in a room having a tem-
perature safely above freezing [32°F (0°C)].
Location
A mechanical room operating under a negative
draft pressure may experience a down draft
in the flue of a boiler when it is not firing.
The cold outside air pulled down the flue
may freeze a heat exchanger. This condition
must be corrected to provide adequate freeze
protection.
Freeze protection for a heating boiler or hot water supply boiler
using an indirect coil can be provided by using hydronic system
antifreeze. Follow the appliance manufacturers instructions. Do
not use undiluted or automotive type antifreeze.
Hydronic systems anti-freeze
Adequate hydronic system antifreeze must be used. A snow
screen should be installed to prevent snow and ice accumulation
around the unit or its venting system.
Outdoor boiler installation
If for any reason, the unit is to be shut o , the following
precautionary measures must be taken:
1. Shut o gas supply.
2. Shut o water supply.
3. Shut o electrical supply
4. Drain the unit completely. Remove one threaded plug
or bulbwell from the inlet side of the front header and
one from the outlet side of the front header on the heat
exchanger. Blow all water out of the heat exchanger
(see FIG.'s 1-2A and 1-2B).
5. Drain pump and piping.
Shut-down and draining
DR
DRAIN PLU
G
G (2X)
Figure 1-2B_Drain the unit_Models 987 - 2067
Installation & Service Manual
DRAIN PLUG
Figure 1-2A_Drain the unit_Models 497 - 747