Page 16
8. - If B-1 vent or an insulated flexible vent pipe cannot be
used as liners, the chimney must be rebuilt to
accommodate one of these methods or some alternate
approved method must be found to vent the appliance.
When inspection reveals that an existing chimney is not
safe for the intended purpose, it shall be rebuilt to conform
to nationally recognized standards, lined or relined with
suitable materials or replaced with a gas vent or chimney
suitable for venting unit heaters. The chimney passageway
must be checked periodically to ensure that it is clear and
free of obstructions.
2
REMOVAL OF UNIT FROM COMMON
VENT
In the event that an existing unit heater is removed from a
venting system commonly run with separate gas applianc-
es, the venting system is likely to be too large to properly
vent the remaining attached appliances. The following test
should be conducted while each appliance is in operation
and the other appliances are not in operation, yet remain
connected to the common venting system. If the venting
system has been installed improperly, the system must be
corrected.
1 - Seal any unused openings in the common venting
system.
2 - Visually inspect the venting system for proper size and
horizontal pitch. Determine there is no blockage or
restriction, leakage, corrosion, or other deficiencies
which could cause an unsafe condition.
3 - In so far as is practical, close all building doors and
windows and all doors between the space in which
the appliances remaining connected to the common
venting system are located and other spaces of the
building. Turn on clothes dryers and any appliances
not connected to the common venting system. Turn
on any exhaust fans, such as range hoods and
bathroom exhausts, so they will operate at maximum
speed. Do not operate a summer exhaust fan. Close
fireplace dampers.
4 - Follow the lighting instructions. Place the appliance
being inspected in operation. Adjust thermostat so
appliance will operate continuously.
5 - Test for spillage at the draft hood relief opening after
five minutes of main burner operation. Use the flame
of a match or candle, or smoke from a cigarette,
cigar, or pipe.
6 - After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers
and any other gas-burning appliance to their previous
condition of use.
7 - If improper venting is observed during any of the above
tests, the common venting system must be corrected.
The common venting system should be resized to ap-
proach the minimum size as determined by using the
appropriate tables in Appendix G in the current editions
of the ANSI Z223-1, or the appropriate Category I Nat-
ural Gas and Propane appliances venting sizing tables
in the current standards of the CSA-B149 for installa-
tion compliance codes.
NOTE - Local codes may supersede any of the provisions
outlined in this instruction.
These unit heaters use a direct spark ignition system.
There is no pilot necessary as the spark lights the main
burner when the gas valve is turned on. The direct spark
ignition control board (A3) emits radio noise as the
sparking process is under way. The level of energy may
be sufficient to disturb a logic circuit in a microprocessor
controlled thermostat. It is recommended that an isolation
relay be used when connecting the unit heaters to a
microprocessor controlled thermostat.
250-400 Units Only: Units are shipped from the factory in
two-stage heating mode. When using a single-stage
thermostat or control, jumper W1 & W2 terminals on
P367 5-pin thermostat plug.
Install the thermostat according to instructions provided.
Route thermostat wiring through knockout on the power
entry box located on the side of the unit heater. Refer to
dimensions in the front of this instruction for location. Use
18 gauge wire or larger for thermostat connections.
Connect thermostat wires to 5-pin P367 thermostat plug
located on the A3 ignition control board. See figure 7. For
ease of installation, disconnect P367 plug from J367,
make wire connections, and replace P367. Refer to
diagram on unit and appropriate diagram in this
instruction.
An additional thermostat wire must be run to terminal “G”
on heater when continuous blower is desired.
(OHFWULFDO&RQQHFWLRQV