31
Check for leaks using an approved chloride-free soap and wa-
ter solution, an electronic combustible gas detector, or other
approved testing methods.
NOTE:
Never exceed specified pressures for testing. Higher
pressure may damage the gas valve and cause subsequent
overfiring, resulting in heat exchanger failure.
Disconnect this unit and shutoff valve from the gas supply piping
system before pressure testing the supply piping system with
pressures in excess of 1/2 psig (3.48 kPa).
Isolate this unit from the gas supply piping system by closing
its external manual gas shutoff valve before pressure testing
supply piping system with test pressures equal to or less than
1/2 psig (3.48 kPA).
T
O
AVOID
THE
POSSIBILITY
OF
EXPLOSION
OR
FIRE
,
NEVER
USE
A
MATCH
OR
OPEN
FLAME
TO
TEST
FOR
LEAKS
.
WARNING
I
F
THE
GAS
FURNACE
IS
INSTALLED
IN
A
BASEMENT
,
AN
EXCAVATED
AREA
OR
CONFINED
SPACE
,
IT
IS
STRONGLY
RECOMMENDED
TO
CONTACT
A
PROPANE
SUPPLIER
TO
INSTALL
A
GAS
DETECTING
WARNING
DEVICE
IN
CASE
OF
A
GAS
LEAK
.
S
INCE
PROPANE
GAS
IS
HEAVIER
THAN
AIR
,
ANY
LEAKING
GAS
CAN
SETTLE
IN
ANY
LOW
AREAS
OR
CONFINED
SPACES
.
P
ROPANE
GAS
ODORANT
MAY
FADE
,
MAKING
THE
GAS
UNDETECTABLE
EXCEPT
WITH
A
WARNING
DEVICE
.
•
•
WARNING
Propane Gas Tanks and Piping
A gas detecting warning system is the only reliable way to de-
tect a propane gas leak. Rust can reduce the level of odorant
in propane gas. Do not rely on your sense of smell. Contact
a local propane gas supplier about installing a gas detecting
warning system. If the presence of gas is suspected, follow
the instructions listed in the
Safety Considerations
section
of this manual.
All propane gas equipment must conform to the safety
standards of the National Board of Fire Underwriters, NBFU
Manual 58.
CANADA: National Standard of Canada, Natural Gas and
Propane Installation Code (NSCNGPIC) CSA B149.1-15.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Propane Gas Installation (Typ.)
Figure 36
For satisfactory operation, propane gas pressure must be 10”
WC at the furnace manifold with all gas appli ances in op
-
eration. Maintaining proper gas pressure depends on three
main factors:
1. Vaporization rate, depending on temperature of the
liquid, and “wetted surface” area of the con tainer
or containers.
2. Proper pressure regulation. (Two-stage regulation is
recommended for both cost and efficiency).
3. Pressure drop in lines between regulators, and
between second stage regulator and the appliance.
Pipe size will depend on length of pipe run and total
load of all appliances.
Complete information regarding tank sizing for vaporiza tion,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and propane gas suppliers.
Since propane gas will quickly dissolve white lead and most stan-
dard com mercial compounds, special pipe dope must be used.
Always use a pipe thread sealant approved for all gases.
Refer to the illustration for typical propane gas installa-
tions and piping.
N
EVER
ALLOW
THE
PRODUCTS
OF
COMBUSTION
,
INCLUDING
CARBON
MONOXIDE
,
TO
ENTER
THE
RETURN
DUCT
WORK
OR
CIRCULATION
AIR
SUPPLY
.
WARNING
Circulating Air & Filters
Duct work - Air Flow
Duct systems and register sizes must be properly designed for
the CFM and external static pressure rat ing of the furnace.
Design the ductwork in accor dance with the recommended
methods of “Air Conditioning Contractors of America” Manual D.
Install the duct system in accordance with Standards of the
National Board of Fire Underwriters for the Installation of
Air Conditioning, Warm Air Heating and Ventilating Systems.
Pamphlets No. 90A and 90B.
A closed return duct system must be used, with the return
duct connected to the furnace.
NOTE:
Ductwork must
never be attached to the back of the furnace.
For upflow
installations requiring 1800 CFM or more, use either two
side returns or bottom return or a combination of side /
bottom. Flexible joints may be used for supply and return
con nections to reduce noise transmission. To prevent the
blower from inter fering with combustion air or draft when a
central return is used, a connecting duct must be installed
between the unit and the utility room wall. Never use a
room, closet, or alcove as a return air chamber.
Checking Duct Static
Refer to your furnace rating plate for the maximum ESP
(external duct static) rating.
Total external static refers to everything external to
the furnace cabinet. Cooling coils, filters, ducts, grilles,
registers must all be considered when reading your total
