INSTALLATION AND OPERATION INSTRUCTIONS
1-12
TANKLESS WATER HEATER 199
Secure joints using appropriate solvent cement to bond the respective pipe
material (Canada: PVC/CPVC cement approved under
ULC-S636, in accordance
with its manufacturer instructions;
USA: PVC (ASTM D2564), or CPVC (ASTM
F493). Use transition cement anywhere that PVC and CPVC are joined. Follow
the cement manufacturer’s instructions closely when joining various components.
For PPs, connections must be secured using approved retainer clips supplied by
the respective PPs manufacturer.
Ensure that all vent connections are liquid and pressure tight. Prior to firing the
unit, and before any of the venting run is concealed by the building construction,
you must test the exhaust joints, using a soap/water solution. You must fill the
condensate trap before testing.
1.4.4 Venting Passage Through Ceiling and Floor
•
Confirm material meets local codes including fire stopping requirements.
Some local jurisdictions require that a minimum initial length of pipe be
exposed or accessible for inspection.
•
Pipe clearances best practice allows a minimum 1/4" gap around the pipe to
prevent binding and expansion noise. Follow local codes.
•
All piping must be liquid and pressure tight.
1.4.5 Rooftop Vent Termination
Direct Vent - Two Pipe
Rooftop vents must terminate as follows:
•
The exhaust pipe can terminate in an open vertical orientation without concern
about rain infiltration; rain will drain away through the condensate trap.
•
The intake air pipe is not typically drained, so it must be terminated with a down-
turned elbow
(see Figure 10).
The intake pipe does not need to penetrate the
roof at the same elevation as the exhaust (as shown); lower down the roof is
OK.
•
The air intake pipe may terminate on the side wall of the building as long as
the air intake terminal is turned down and the side wall of the building is not
exposed to large wind loads i.e.: prevailing winds. (
see Figure 9
)
WARNING
Condensate can cause
corrosion of metal roofing
components and other
roofing materials. Check
with the builder or roofing
contractor to ensure that
materials are resistant to
acidic condensate. pH levels
can be as low as 3.0
[18" (457 mm) Canada] MIN.
NOTE: THE BIRD SCREEN
IS OPTIONAL IN COLD
WEATHER CLIMATES
CAUTION
Vent termination clearances
in this section are code
minimum, or recommended
minimum requirements,
and may be inadequate for
your installation. You must
examine building envelope
details, and take measures to
avoid admission of moisture
into building structures.
Serious structural damage
may occur if adequate
precautions and clearances
are not allowed for.
These precautions are to be
observed for neighboring
structures as well as for
the structure the unit(s) are
installed in.
Figure 10: Rooftop vent terminal configurations
Figure 9: Rooftop vent terminal
configurations