Install Instructions

32
DANGER
Any signs of condensate seepage at the base of
the chimney shall be inspected immediately. The
discoloration may be a sign of chimney damage and
must be remedied immediately.
C. DRAFT
1. The natural draft generated through a chimney is dependent
on several factors including, chimney height, temperature
of ue gases, cross section area of chimney, chimney
wall insulation value, dilution air and total volume of
ue gases, to name a few. Make sure that the boiler has
been running for at least 5 minutes before measuring the
draft.
2. Minimum Draft at Breech (Canopy) – The draft induced
by a chimney must create at least a pressure of 0 (zero)
inches water column (“ w.c.) at the pressure tapping on
the canopy mounted on rear of boiler (see Figure 17).
The pressure at the canopy cannot be positive since this
could create a condition that allows ue gas by-products
to escape from the draft regulator. A negative pressure
reading up to -.03 inches water column is acceptable for
proper operation. (See Tables 15A thru 15C and 16)
Burner Specications at the rear of this manual for more
details)
3. Minimum Overre Pressure – The overre pressure is
another piece of information that is often measured,
however this should be done for observation purposes
only! The breech pressure must be used to qualify the
draft condition. See Tables 15A thru 15C and 16 for
more details as a guide. Actual draft and temperature
measurements may be different then those values in the
table.
D. STACK TEMPERATURE
1. The temperature of the ue gases has a signicant effect
on the amount of draft created in a vertical chimney as
well as the propensity to create condensate. The higher
the stack temperature, the greater the amount of draft
that can be generated. A lower stack temperature not
only reduces the amount of draft that can be created but
it also increases the possibility that the ue gases could
condense in the chimney connector or stack.
2. NFPA 31 and CSA B139-04 have information to help the
installer make an appropriate choice of venting materials.
In some cases a chimney may have to be lined to create
sufcient draft. In other cases, the chimney may have to
be lined to prevent the corrosion of a masonry chimney.
Consult with a chimney specialist knowledgeable on the
requirements for chimney requirements in your area.
CAUTION
Any doubt on the condition of a chimney or it’s
ability to prevent the generation and accumulation
of ue gas condensate, must be relined according
to NFPA 31 (United States) or CSA B139 (Canada).
CAUTION
Use the chimney venting tables as a guide. It is
highly recommended that any borderline application
should result in the relining of the chimney with
a suitable liner that creates sufcient draft and
to protect against corrosion caused by ue gas
condensate.
3. Bafes – The efciency of the boiler is based on the
insertion of ue bafes supplied with your product.
Under no circumstances are other bafes to be used on
this product. Refer to Section II, Item F, Paragraph 7 for
bafe installation. If there is any doubt on the application
of this boiler on the intended chimney, consult with your
local code ofcials. At a minimum, remove the bafes to
increase the stack temperature. See Tables 15A thru 15C
and 16 for temperature differential (∆T) with bafes IN
and OUT. In addition, the lower the CO
2
level the higher
the stack temperature.
WARNING
Remove the bafes if there are any signs of
condensation in the chimney or chimney connector.
Consult with your local chimney professional for
recommendations.
Figure 17: Smokebox Pressure Tapping for
Checking Draft at Breech
V. NATURAL DRAFT VENTING (continued)