LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 15)

Page 11 N eo T herm Boilers and Water heaters
All installations should be done following the vent supplier’s
recommended installation techniques. If manufacturer’s
instructions are not available for the material used, follow the
Laars recommendations.
The vent pipe must pitch upward, toward the vent terminal,
not less than 1/4” per foot, so that condensate will run back
to the NeoTherm to drain. Route vent pipe to the heater as
directly as possible. Seal all joints and provide adequate
hangers as required in the venting system manufacturer’s
Installation Instructions. Horizontal portions of the venting
system must be supported to prevent sagging and may not
have any low sections that could trap condensate. The unit
must not support the weight of the vent pipe. Please see Table
2 for proper diameter vs. length allowed.
IMPORTANT NOTE ABOUT COMMON VENTING: A
single vent that is shared by multiple NeoTherm units
MUST be engineered by a competent venting specialist,
and involves the selection of draft inducing equipment,
hardware and controls to properly balance flue gas
pressures. Do not common vent NeoTherm units
unless the vent system meets this requirement.
NeoTherm units are never permitted to share a vent
with Category I appliances.
Venting Requirements Unique to Canada
NeoTherm boilers and water heaters are Vent Category IV
appliances. Per the requirements of CAN/CSA-B149.1,
only BH vent systems can be connected to these units and
such vent systems, either ULC S636 certified stainless steel
or other ULC S636 certified BH vent (eg. plastics) must be
installed per the vent manufacturer’s certified installation
instructions.
As a result, two items listed in the Unpacking section (Figure
8) are not included with NeoTherm units for Canada
(underlined):
A
exhaust vent terminal (not included)
B. air intake terminal
C. temperature/pressure gauge kit
D. circulator pump/wire harness (units with pump)
E. CPVC exhaust pipe section (80-500) (not incl.)
F. outdoor/system sensor kit
G. flow switch kit (399-850)
H. alternate size vent/terminal screens
J. exhaust vent adapter CPVC/ST ST (750-850)
It is the responsibility of the appropriately licensed technician
installing this NeoTherm unit to use ULC S636 certified vent
material consistent with the requirements as described in the
Venting and Combustion Air section.
Class I venting systems are suitable for gas-fired appliances
producing flue gas temperature of more than 135°C, but not
more than 245°C.
Class II venting systems are suitable for gas-fired appliances
producing flue gas temperatures of 135°C or less.
Class II venting systems are further classified into four
temperature ratings as follows:
A
Up to and including 65°C
B Up to and including 90°C
C Up to and including 110°C, and
D Up to and including 135°C
IMPORTANT! It is also the responsibility of the installer
to ensure that a flue gas sampling port is installed in the vent
system. This flue gas sampling port must be installed near the
flue connection of the NeoTherm unit: within 2 feet of the
flue connection. There is no flue gas sampling port internal
to the NeoTherm, so one must be installed in the vent system
external to the NeoTherm unit. A flue gas sampling port
available as a component of the ULC S636 certified vent
system is preferred. However, if one is not available with
the certified vent system, Laars suggests using a tee with the
branch connection sized to allow for insertion of a flue gas
analyzer probe. The branch connection must be resealable
with a cap or other by other means to ensure the vent system
remains sealed. (See Figure 11.)
Consideration must be given to the placement and orientation
of the flue gas sampling port to ensure that condensate is free
to flow back into the NeoTherm unit and not collect anywhere
in the vent system - including in the flue gas sampling port.
An exhaust vent terminal must be installed. If an exhaust vent
terminal is not available with the certified vent system, Laars
suggests the use of a coupler fitting from the certified vent
system into which the vent terminal screen, included with the
Figure 11 - Test Port - ULC-S636 system