3. Breeching
•
See Table 2 for minimum recommended breeching and chimney sizes.
•
Keep run boiler to chimney as short as possible.
•
Use as few elbows as possible.
•
Slope upward towards chimney at not less than 1/4” per foot.
•
Use a sealed-in thimble for the chimney connection.
•
Connect together all sections and/or fittings with sheet metal screws and
seal with silicone sealant.
4. When more than one appliance is connected to the same chimney, the chimney’s
internal cross-sectional area must be at a minimum equal to the area of the largest
vent plus 50% of the area of each additional vent.
5. Clearances—vent pipe between boiler and chimney must be a minimum of 6”
from any combustible material.
MINIMUM RECOMMENDED BREACHING AND CHIMNEY SIZE.
Boiler Model
Min. Breeching
Dia.
Min. Recommended
Chimney Size
I.D. HT
.
OWB-9
6”
6” 15’
OWB-15
7”
7” 15’
OWB-25
7”
8” 20’
OWB-35
10”
10” 15’
OWB-50
10”
10” 15’
Table 2.
6. An oil-fired unit shall be connected to a flue having sufficient draft at all times, to
assure safe proper operation of the unit.
Installation, Operation, And Service Instructions
17
