LAARS Heating Systems
Page 22
4.7 Air Supply and Vent Connections at the Appliance
4.7.2 Direct Venting
The boiler uses 3˝ or 2˝ diameter exhaust and 3˝
or 2˝diameter intake air ducts. To ensure the draw
of air directly from and exhaust of air directly to the
outside of the building, create an airtight seal from
the boiler collar to the vent termination.
(For installations in Canada)
field-supplied plastic
vent piping must comply with CAN/CSA B149.1
(latest edition) and be certified by the Standard
For Type BH Gas Venting Systems, ULC-S636.
Components of this listed system must not be
interchanged with other vent systems or unlisted
pipes or fittings. All plastic components and
specified primers and glues of the certified vent
system must be from a single system manufacturer
and must not be intermixed with another system
manufacturer’s parts.
Tightening — Boiler Collar (Socket) to Vent
Pipe & Inlet Pipe
- Clean and dry your selected PVC, CPVC vent
pipe and Laars Boiler collar (socket).
- You can select to the size of vent pipe(2˝ & 3˝),
according to the installation conditions.
- Push the pipe into the collar (socket) until it
touches the bottom of the socket fitting.
- For 2” installations, install a field supplied 3” to
2” adaptor. Adaptor must be installed in vertical
section of piping only.
Boiler model
3˝ Combustion Air / Vent Pipe
2˝ Combustion Air / Vent Pipe
Max
Elbow Max
Max
Elbow Max
MFTCW140
100´ (30M)
6
50´ (15M)
4
Table 6. Maximum Vent / Air Pipe Lengths for either 3” or 2 “ Pipes
2” pipe connected, using an adapter
3” to 2”
adapter
is NOT
included.
3” pipe
4.7.1 Vent / Air Pipe Lengths
Note : For additional elbows, reduce maximum allowable length
• 5 feet (1.5M) for each additional 3-inch 90-degree elbow
• 2.5 feet (0.75M) for each additional 3-inch 45-degree elbow
• 5 feet (1.5M) for each additional 2-inch 90-degree elbow
• 4 feet (1.2M) for each additional 2-inch 45-degree elbow
• The thickness of the wall vents installed : Min 4˝ ~ Max 20˝
NOTE: When using a 2” vent pipe, DIP Switch 4 must be in the OFF position. Be sure to power
Off the Mascot FT before changing DIP switches.
For 3” Pipe vent, the default setting for DIP 4 is ON.
Refer to Section 4.19
