11
Servicing should only be performed by a Qualified Service Technician
VENTING TABLES – BTH 120 ‑ 250
Maximum equivalent feet of intake and vent pipe using 3" PVC is 50 feet (15.2 m). Equivalent feet must
include any 90° elbows (two 45° elbows equal one 90° elbow). Three inch diameter 90° elbows are
equivalent to 5' (1.5 m) of pipe.
Maximum equivalent feet of intake and vent pipe using 4" PVC is 120 feet (36.6 m). Equivalent feet
must include any 90° elbows (two 45° elbows equal one 90° elbow). Four inch diameter 90° elbows are
equivalent to 5' (1.5 m) of pipe. If vent size is increased to extend the maximum allowed distance, it cannot
be decreased again anywhere in the vent run.
Vent Length Table Equivalent Feet (Meters) 120 through 250
Number of 90° Elbows
3" Minimum Pipe (Ft./M.)
3" Maximum Pipe (Ft./M.)
4" Maximum Pipe (Ft./M.)
ONE (1)
7/2.1
45/13.7
115/35
TWO (2)
7/2.1
40/12.2
110/33.5
THREE (3)
7/2.1
35/10.7
105/32
FOUR (4)
7/2.1
30/9.1
100/30.5
FIVE (5)
7/2.1
—
95/29
SIX (6)
7/2.1
—
90/27.4
VENTING TABLES – BTH 300, 400, 500
Maximum equivalent feet of intake and vent pipe using 4" PVC is 70 feet (21.3 m). Equivalent feet must
include any 90° elbows (two 45° elbows equal one 90° elbow). Four inch diameter 90° elbows are equivalent
to 5' (1.5 m) of pipe.
Maximum equivalent feet of intake and vent pipe using 6" PVC is 120 feet (36.6 m). Equivalent feet must
include any 90° elbows (two 45° elbows equal one 90° elbow). Six inch diameter 90° elbows are equivalent
to 5' (1.5 m) of pipe.
Vent Length Table Equivalent Feet (Meters) 300, 400, 500
Number of 90° Elbows
4" PVC Maximum
Feet/meters of Pipe (Ft./M.)
6" PVC Maximum
Feet/meters of Pipe (Ft./M.)
ONE (1)
65'/19.7
115'/35.0
TWO (2)
60'/18.2
110'/33.5
THREE (3)
55'/16.7
105'/32.0
FOUR (4)
50'/15.2
100'/30.5
FIVE (5)
45'/13.6
95'/29.0
SIX (6)
40'/12.1
90'/27.4
