Placement And Installation - Lennox G32V Series Service Literature

9 − Operate unit and observe draft gauge reading. Read-
ings will change as heat exchanger warms.
a. Take one reading immediately after startup.
b. Take a second reading after unit has reached steady
state (approximately 5 minutes). Both readings should
fall above the line shown in figure 32.
10− Compare readings to figure 32. Be sure to compare
only like readings (compare startup reading to startup
reading, then compare steady state reading to steady
state reading). Subtract the absolute steady state read-
ings from one another. This will be the pressure differ-
ential. In order for the furnace to operate, the larger
negative must always be on the combustion air
blower side of the switch.
Example − one side of the pressure switch reads .60"
and the other side of the pressure switch reads .10".
Pressure differential is .60" − .10"= .50"
The pressure differential should be greater
than the settings in table 30.
11− When test is complete, remove thermostat demand
and allow unit to cycle off.
12− Remove draft gauge and Tee. Reinstall pressure
switch sensing hose to left side of pressure switch.
If pressure switch does not close at start up or differential is
less than set point the following should be checked.
1 − Restriction in exhaust and or intake vent.
2 − Pressure switch lines are routed correctly and for dam-
age.
3 − Condensate in pressure switch lines.
4 − Wiring of pressure switch to furnace.
5 − Blocked heat exchanger or leak in heat exchanger.
II−PLACEMENT AND INSTALLATION
Make sure unit is installed in accordance with installation in-
structions and applicable codes.
A−PVC Joint Cementing Procedure
WARNING
DANGER OF EXPLOSION! Fumes from PVC glue
may ignite during system check. Remove spark
plug wire from ignition control before 120V power
is applied. Reconnect wire after two minutes.
1 − Measure and cut vent pipe to desired length.
2 − Debur and chamfer end of pipe, removing any ridges or
rough edges. If end is not chamfered, edge of pipe may
remove cement from fitting socket and result in a leak-
ing joint.
3 − Clean and dry surfaces to be joined.
4 − Test fit joint and mark depth of fitting on outside of
pipe.
5 − Uniformly apply liberal coat of PVC primer for PVC or
ABS cleaner for ABS for at least 5 to 15 seconds to inside
socket surface of fitting and male end of pipe to depth of
fitting socket. Remove puddles of primer before applying
cement.
6 − Promptly apply solvent cement to end of pipe and in-
side socket surface of fitting. Cement should be ap-
plied lightly but uniformly to inside of socket. Take care
to keep excess cement out of socket. Apply second
coat to end of pipe.
NOTE−Time is critical at this stage. Do not allow primer
to dry before applying cement.
7 − Immediately after applying last coat of cement to pipe,
and while both inside socket surface and end of pipe
are wet with cement, forcefully insert end of pipe into
socket until it bottoms out. Turn pipe 1/4 turn during as-
sembly (but not after pipe is fully inserted) to distribute
cement evenly. Once joint is made, PVC may swell.
Hold joint together until bonded (approximately 20 sec-
onds).
NOTE−Assembly should be completed within 20 sec-
onds after last application of cement. Hammer blows
should not be used when inserting pipe.
8 − After assembly, wipe excess cement from pipe at end
of fitting socket. A properly made joint will show a bead
around its entire perimeter. Any gaps may indicate a
defective assembly due to insufficient solvent.
9 − Handle joints carefully and support properly until com-
pletely set.
B−Venting Considerations
The thickness of construction through which vent/air intake
pipes may be installed is 24" (610mm) maximum and 3"
(76mm) minimum. If a G32V furnace replaces a furnace
which was commonly vented with another gas appliance, the
size of the existing vent pipe for that gas appliance must be
checked. Without the heat of the original furnace flue prod-
ucts, the existing vent pipe may be oversized for the single
water heater or other appliance. The vent should be checked
for proper draw with the remaining appliance.
Insufficient combustion air can cause head-
aches, nausea, dizziness or asphyxiation. Exces-
sive exposure to contaminated combustion air
will result in safety and performance related
problems. Avoid exposure to the following sub-
stances in the combustion air supply:
Permanent wave solutions;
Chlorinated waxes and cleaners;
Chlorine base swimming pool chemicals;
Water softening chemicals;
De−icing salts or chemicals;
Carbon tetrachloride;
Halogen type refrigerants;
Cleaning solvents (such as perchloroethylene);
Printing inks, paint removers, varnishes, etc.;
Hydrochloric acid;
Cements and glues;
Antistatic fabric softeners for clothes dryers; and
Masonry acid washing materials.
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CAUTION