INSTALLATION AND OPERATION INSTRUCTIONS
1-8
SL 80-399 MODULATING GAS BOILER
SL 26-260 G3, SL 40-399 G3 MODULATING GAS BOILERS
SL 40-399 G3
EXHAUST PIPE SIZE
MAXIMUM EQUIVALENT LENGTH
Sched.40; Rigid PPs
4" CPVC / Rigid PPs
200' (each side)
90° vent elbow
allow 8' equivalent
90° long sweep elbow
allow 5' equivalent
45° elbow
allow 3' equivalent
PPs 87-90° elbows
use 8' equivalent
3" Stainless Sidewall Terminal (SST)
IBC P/N 180-149 (P-257)
allow 65' equivalent
3" CPVC (to adapt to the SST)
for each 1' allow 3.2' equivalent
Flexible PPs
4" PPs Flexible
160' max, using 1.2 x for equivalent length
Table 3B: Maximum Exhaust Venting Length for SL 40-399 G3
For Flexible PPs, up to 160 actual lineal feet are allowed in a nominally vertical orientation
(>45°). The equivalent length of 4” Flex PPs shall be computed using a multiple of 1.2:1,
e.g.80' x 1.2 = 96’ equivalent (with such use of 80' of 4" Flex, up to 104' equivalent of 4" Rigid
PPs would still be allowed). PPs 87-90° elbows are considered equivalent to 8'.
NOTE:
Unused intake travel cannot be added to the exhaust. Unequal intake and exhaust
piping is allowed - see Section 1.4.8.
Exhaust venting must slope down towards the boiler with a pitch of at least 1/4" per foot
(PPs vent: follow PPs manufacturer requirements for slope), so condensate runs back
towards the trap. Support should be provided for intake and vent piping, particularly so for
horizontal runs (follow local code).
Ensure all venting components are clear of burrs/debris prior to assembly. Care is to be
taken to avoid ingestion into the fan of plastic debris left in the combustion air piping.
All joints must be secured using appropriate solvent cement to bond the respective
pipe material (Canada: CPVC cement approved under ULC-S636, in accordance
with its manufacturer instructions; USA: PVC (ASTM D2564), or PVC/ABS (D2235)
- Use transition glue anywhere that PVC and CPVC are joined. Follow the cement
manufacturer’s instructions closely when joining various components. For PPs,
connections shall be secured using approved retainer clips supplied by the respective PPs
manufacturer.
Figure 4: Pipe and fitting beveling
