John Wood Power Vent (Non-ENERGY STAR qualified models) - Manual (Page 10)

Exhaust Venting
This heater is designed to exhaust the products of combus-
tion (flue gases) to the outdoors using a sealed piping sys-
tem. Table 2 lists the allowable vent materials and sizing
information. Figure 8 shows the general venting layout while
Figures 9-12 show various end termination details and
clearances. Connection of the venting piping to the blower
is shown in Figures 13-15.
Correct installation of the venting system is essential to the
safe and efficient operation of this water heater. Vent piping
must be installed in accordance with all applicable local and
provincial or state codes. In the absence of such codes, all
installation shall meet the requirements as stated in the lat-
est edition of the "Natural Gas and Propane Installation
Codes" CAN/CSA-B149-1 (Canada) or "National Fuel
Gas Code" ANSI Z223.1 (NFPA 54) (U.S.A.).
Note: The information provided in Figure 6 is intended as a
guideline for good vent installation practices only and is not
intended to restrict venting options beyond those restric-
tions established by the latest edition of the "Natural Gas
and Propane Installation Codes" CAN/CSA-B149-1 or
any applicable local and provincial codes.
Important Notes and Warnings
• This heater is certified to be installed using Schedule 40
PVC or CPVC plastic vent material. In Canada some
jurisdictions require that this material is approved to
ULC S636. ULC S636 mandates that components from
different systems must not be mixed in the same vent
runs. Check local codes to determine which materials
are allowed in your area and only use approved materi-
al. All venting material and components must be joined
with the approved primer/cleaner and solvent cement.
• Do not common vent this heater with any other appli-
ance.
• 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 poses 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 condensa-
tion in the vent piping. When using long runs of venting
or when the venting passes through cold or unheated
areas, considerable 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 col-
lected 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.
• Be aware of any concealed wiring or piping inside the
walls.
• Ensure sufficient ventilation air to prevent elevated tem-
peratures in closets and confined spaces.
– 10 –
VENT LENGTH LESS THAN OR
EQUAL TO 6.1 EQUIVALENT METRES
(20 FT.) USE THIS SCREEN.
VENT LENGTH GREATER THAN 6.1
EQUIVALENT METRES (20 FT.) USE
THIS SCREEN.
Figure 7 Rodent Screens
PREFERRED PRACTICE
150mm
(6 in.) min.
STREET ELBOW NORMAL ELBOW
BACK TO BACK ELBOWS
Figure 6 Pipe Fittings And Practices
90° LONG SWEEP ELBOW
(LESS RESTRICTIVE)
90° SHORT SWEEP ELBOW
(MORE RESTRICTIVE)