®
WATER
BOILER
—
Boiler Manual
Connect breeching
(continued)
&IGURE
Breech connection, typical, for gravity venting into chimney
UO011
Typical locations for barometric
draft control (also see draft
control manufacturer's instructions)
Chimney venting
(continued)
Connect breeching:
,ONG HORIZONTAL BREECHINGS EXCESSIVE
number of tees and elbows or other ob-
structions restricting combustion gas flow
can result in possibility of condensation,
flue gas leakage and carbon monoxide
emissions, which can lead to severe per-
sonal injury or death.
#ONNECT FULLSIZED BREECHING WHEN POSSIBLE 3EE
Table 2, page 12, and Figure 5, below.
2. Connection must be made above bottom of chimney
to avoid blockage. Breeching must not enter chim-
NEYFARENOUGHTOCAUSEOBSTRUCTION5SETHIMBLEOR
slip joint where breeching enters chimney to allow
removal for cleaning.
3. When burner and boiler are properly installed,
breeching draft will be approximately -0.01” to
-0.02” W.C. Install barometric control in breech-
ing, per control manufacturer’s instructions, when
excess draft needs to be relieved or to comply with
APPLICABLECODESANDREGULATIONS5SEDRAFTGAUGETO
adjust proper opening.
4HE5LTRA/ILBOILERISCAPABLEOFBEING
PRESSURElRED/VERlREPRESSUREMAYBE
positive even with a negative pressure
INTHECHIMNEY3EETHE2ATINGSTABLEON
page 39 for boiler draft loss.
The pressure in the breeching and chim-
ney must always be negative unless the
chimney and breeching are constructed
OF VENT PIPING DESIGNED FOR PRESSURIZED
venting.
4. An induced draft fan for the chimney may be neces-
sary if:
s %XCESSIVERESISTANCETOFLOWOFCOMBUSTIONGASES CAN
be expected.
s #ROSSSECTIONALAREAOFCHIMNEYISSMALLERTHANMINI
-
mum recommended.
s #HIMNEYHEIGHTISLESSTHANRECOMMENDED
5. When using an induced draft fan:
s 3EALALLVENTJOINTS
s )NTERLOCKBURNERWITHFANOPERATION
Part number 550-141-986/0112
13
