10
NOTE:
In addition to the required clearances to combustible
materials, a minimum of 24 inches service clearance must be
available in front of the unit.
T O P
B O T T O M
S ID E
S ID E
S ID E
T O P
B O T T O M
U pflow
C ou nte rflo w
H orizo n ta l
Figure 3
E
XISTING
F
URNACE
R
EMOVAL
NOTE:
When an existing furnace is removed from a venting
system serving other appliances,
the venting system may be
too large to properly vent the remaining attached appliances.
The following vent testing procedure is reproduced from
the
American National Standard/National Standard of
Canada for Gas-Fired Central Furnaces ANSI Z21.4, CSA-
2.3 latest edition Section 1.23.1.
The following steps shall be followed with each appliance
connected to the venting system placed in operation, while
any other appliances connected to the venting system are
not in operation:
1. Seal any unused openings in the venting system;
2. Inspect the venting system for proper size and hori-
zontal pitch, as required by the National Fuel Gas Code,
ANSI Z223.1 or the Natural Gas and Propane Installa-
tion Code, CSA B149.1-15 and these instructions. De-
termine that there is no blockage or restriction, leak-
age, corrosion and other deficiencies which could cause
an unsafe condition.
3. As far as practical, close all building doors and win-
dows and all doors between the space in which the
appliance(s) connected to the venting system are lo-
cated and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected
to the venting system. Turn on any exhaust fans, such
as range hoods and bathroom exhausts, so they shall
operate at maximum speed. Do not operate a summer
exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected in operation. Adjust thermostat so
appliance shall operate continuously.
7. Test for spillage from draft hood appliances at the
draft hood relief opening after 5 minutes of main
burner operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the above
tests, the venting system must be corrected in accor-
dance with the National Fuel Gas Code ANSI Z223.1/
NFPA 54 and/or National Gas and Propane Installation
Code CSA B149.1-15.
9. After it has been determined that each appliance con-
nected to the venting system properly vents when
tested as outlined above, return doors, windows, ex-
haust fans, fireplace dampers and any other gas burn-
ing appliance to their previous conditions of use.
If resizing is required on any portion of the venting system,
use the appropriate table in Appendix G in the latest edition
of the National Fuel Gas Code ANSI Z223.1 and/or
CSA B149.1-15 Installation Codes.
T
HERMOSTAT
L
OCATION
The thermostat should be placed approximately five feet
from the floor on a vibration-free, inside wall in an area
having good air circulation. Do not install the thermostat
where it may be influenced by any of the following:
• Drafts, or dead spots behind doors, in corners, or
under cabinets.
• Hot or cold air from registers.
• Radiant heat from the sun.
• Light fixtures or other appliances.
• Radiant heat from a fireplace.
• Concealed hot or cold water pipes, or chimneys.
• Unconditioned areas behind the thermostat, such
as an outside wall.
Consult the instructions packaged with the thermostat for
mounting instructions and further precautions.
C
OMBUSTION
& V
ENTILATION
A
IR
R
EQUIREMENTS
T
O
AVOID
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
,
SUFFICIENT
FRESH
AIR
FOR
PROPER
COMBUSTION
AND
VENTILATION
OF
FLUE
GASES
MUST
BE
SUPPLIED
. M
OST
HOMES
REQUIRE
OUTSIDE
AIR
BE
SUPPLIED
INTO
THE
FURNACE
AREA
.
WARNING
Improved construction and additional insulation in buildings
have reduced heat loss by reducing air infiltration and es-
cape around doors and windows. These changes have helped
in reducing heating/cooling costs but have created a prob-
lem supplying combustion and ventilation air for gas fired
and other fuel burning appliances. Appliances that pull air
out of the house (clothes dryers, exhaust fans, fireplaces,
etc.) increase the problem by starving appliances of air.
House depressurization can cause back drafting or improper
combustion of gas-fired appliances, thereby exposing build-
ing occupants to gas combustion products that could include
carbon monoxide.
