Demand Duo
™
H
-
Series Installation and Operation Manual
36
When installing PVC/CPVC Common Vent,
follow these guidelines:
•
Avoid sharp bends or tees in the vent
system. These vent components create
additional restrictions that could reduce
performance of the water heaters.
•
PVC combustion air and exhaust should
terminate with elbow or tee pointing down.
This will stop unwanted moisture from
entering the vent system.
•
Fire rated penetrations shall be firestopped.
Contact your vent supplier or local firestop
manufacturer for appropriate firestop
methods.
•
Examine all vent components for damage
prior to installation.
•
PVC/CPVC vent systems must be free to
expand and contract. Refer to the vent
manufacturer
’
s installation instructions for
appropriate support methods.
•
PVC/CPVC venting must include unrestricted
vent movement through walls, ceilings, and
roof penetrations.
•
Use only PVC/CPVC primer and cement
approved for use by the vent manufacturer.
•
Keep solvents away from heat, sparks,
flames and all other sources of ignition.
•
Do not solder, cut or weld until all vapors
have dissipated.
•
PVC solvents are heavier than air causing
them to settle at low points of the system.
•
Before using PVC solvent
−
Disconnect power to the water heater.
−
Remove the front cover of the water
heater.
−
Ensure areas around the water heater
and PVC venting are all well ventilated.
−
Allow all vapors to dissipate before
applying power to the system or
introducing any other source of ignition.
PVC solvents (primer
and glue) can be
extremely flammable. Vapors may cause a
flash fire or explosion resulting in property
damage, personal injury or death.
WARNING
DO NOT
DO NOT mix vent pipe, fittings
or joining
methods from different vent manufacturers.
DO NOT attempt to repair damaged vent.
Damaged vent components must be re-
placed.
DO NOT use short radius elbows in the com-
mon vent system.
ACCEPTABLE
ACCEPTABLE
90° Elbows, Long
Sweep
90° Elbows, Short
Sweep
HEADER
VENT
PVC/CPVC Common Vent Installation
•
Refer to vent manufacturer
’
s installation in-
structions for proper joint assembly proce-
dures and products.
•
PVC/CPVC common venting should include a
condensate drain and trap between the head-
er and vent length. Condensate trap must
include a loop that can hold 6 in. (15 cm) of
water. See
“
PVC/CPVC Common Vent Instal-
lation
”
illustration on this page.
NOT ACCEPTABLE
90° Elbows,
Close Turn
Figure 39
