Install Instructions

31
2. Type B Chimney Connector - a type B chimney
connector can be used to transmit the ue gases
provided ue gas temperature entering the chimney
connector is greater than 310°F.
3. Type L Chimney Connector - a type L vent or
other suitable material shall be used for a chimney
connector if the temperature or exiting temperature
is less than 310°F.
DANGER
Any signs of condensate see page 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 8 thru 8B, 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 8 thru 8B 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 has 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 NFPA31.
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. The bafes are installed in the 2
nd
pass (two inner ueways) on the MST396, MST513
and MST629 Refer to Section II, Item E, Paragraph
1 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
Figure 17: Smokebox Pressure Tapping for
Checking Draft at Breech
SECTION V: VENTING & AIR INTAKE PIPING (continued)