14
Fig. 15
• This heater is certified to be installed using PVC, CPVC, ABS
or polypropylene plastic vent material. Check with your local
authorities to determine which materials are allowed in your
area. All venting material and components must be joined with
the approved primer/ cleaner and solvent cement or mechanical
seals (see “Polypropylene Vent Systems”).
• Do not common vent this heater with any other appliance.
• Do not allow insulation to cover the vent piping.
• During operation the plastic piping will expand as it heats up and
contract as it cools down. This is normal for this type of venting.
Rigidly fastening the vent piping can cause undue stress that may
result in the cracking or fracturing the vent piping material. A
fracture of the venting pipe may pose a serious safety hazard. To
prevent stressing of the vent system, all hangers and supports
must allow the vent piping freedom to move.
• Use long sweep elbows wherever possible. Closely coupled
elbows and short radius elbows can reduce the venting capacity.
• All power vented water heaters generate a certain amount
of operational noise. In order to minimize noise transmission
to the support structure, use isolation pads between the pipe
hangers and the vent pipe.
• Most power vent installations develop some condensation in
the vent piping. When using long runs of venting or when the
venting passes through cold or unheated areas, cotnsiderable
amounts of condensate from the flue gases can develop.
Provision must be made for the condensate to drain freely from
the system or to be collected in a condensate trap(s) that can
be drained. Damage or fracture of the vent piping may occur
if the condensate is allowed to collect and freeze. Pooling of
condensate can restrict airflow and can cause nuisance failures
of the system.
• In regions that experience freezing conditions, slope the venting
back towards the heater so that the condensate will drain back
to the blower and be collected in the condensate trap. Draining
condensate out through the termination can result in vent
freeze up resulting in a nuisance shut down situation. Ice formed
from frozen condensate can cause a safety hazard. See also
notes in the “Venting” section.
Venting terminations and sizing
• Heaters are supplied with a 3”x 2” rubber coupling to attach the
venting to the blower and a 2”, 45° vent termination elbow.
• Supplied with this heater is a vent termination screen (see
Figure 15).
Installed in the vent termination elbow, the vent screen is required
to keep foreign objects, rodents and small birds from entering the
venting system. This screen has been sized to ensure maximum
energy efficiency of the vent system based on the “equivalent
length” of the vent piping. (see Figure 15).
How to determine the “equivalent length” is shown in Figure
in Table 1.
Vent screen installation
• Install the vent screen into the vent termination elbow.
• Gently push the screen into the termination elbow until it
sits against the inside shoulder.
• The metal wire screens are self-securing.
IMPORTANT NOTES AND WARNINGS
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