Munchkin OFB User manual

Venting Manual
for
Munchkin Oil Fired Boilers
Designed and Tested to the A.S.M.E. Boiler and Pressure Vessel Code
LP-115 REV 6/1/03

CONTENTS / USING THIS MANUAL
1
TABLE OF CONTENTS
PART I. COMBUSTION AIR AND VENTILATION 2
A. Fresh Air Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
B. Air for Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
C. Combustion Air Supply with No Barometric Damper . . . . . . . . . . . . . . . . . . . . . . . . .3
PART II. VENTING REQUIREMENTS 3
A. Neutral Point Pressure Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
B. Roof Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
C. Heat Extractors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
PART III. NATURAL DRAFT APPLICATIONS 4
PART IV. MECHANICAL DRAFT APPLICATIONS 5
PART V. POWER VENTER APPLICATIONS 6
PART VI. DIRECT VENT APPLICATIONS 7
A. Installing The Joint Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
B. Installing The Outside Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
C. Connections To Outside Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
D. Connections To Appliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
PART VII. MAINTENANCE 10
PART VIII. CERAFLEX “FLEX L” COMPONENTS LIST 11
DANGER
Indicates a condition or hazard which
will cause severe personal injury, death
or major property damage.
SPECIAL ATTENTION BOXES
Throughout this manual you will see these
special attention boxes similar to this one,
which are intended to supplement the
instructions and make special notice of
potential hazards. These categories mean, in
the judgement of Heat Transfer Products, Inc.:
WARNING
Indicates a condition or hazard which
may cause severe personal injury,
death or major property damage.
CAUTION
Indicates a condition or hazard which
will or can cause minor personal injury
or property damage.
USING THIS MANUAL

COMBUSTION AIR AND VENTILATION
2
The purpose of this manual is to guide an installer through the installation of a MUNCHKIN
OFB boiler for use in any venting application considered as 'good industry practice' and
must conform with all Federal, State and local codes requirements and further follow the
guidelines called out in NFPA31 and NFPA211.
PART I. COMBUSTION AIR AND VENTILATION
If a MUNCHKIN OFB is being used for a retrofit and is installed in a full basement with ade-
quate infiltration for combustion air it may be installed in the usual way following accepted
industry guidelines and good industry practices.
A. FRESH AIR INTAKE
Recent energy conservation practices have resulted in many people insulating and caulking
their homes to a level where the fresh air required for efficient combustion is not always
readily available. Particularly if you choose to isolate your MUNCHKIN OFB in an enclosed
area of your home, a fresh air intake must be installed in this area.
B. AIR FOR COMBUSTION
The MUNCHKIN OFB boiler must have an assured supply of combustion air. A dedicated
outside supply of air through an installed duct or pipe should be installed at or within 5 ft.
of the boiler. A shut-off damper may automatically control the supply duct when the unit is
not operating, but the operating automatic damper must 'fail' in the open position. The com-
bustion air duct must have direct access to the outdoors and have a rain hood and insect
screen installed at the outside wall.
Care should be taken when the boiler is to be installed within a home where the operation
of exhaust fans, attic fans, kitchen ventilation systems, new high efficiency clothes dryers or
fireplaces may create severe negative vent pressures and unsatisfactory combustion and
venting conditions. Special provisions should be made for additional make-up air to supply
the other air requirements.
In cases of electric heat conversions or any structure of tight construction an opening of one
(1) square inch of minimum free area per 1000 BTU per hour of burner input must be pro-
vided. The air supply to the burner must be provided directly to the burner and originate
outside the structure within five feet (5') of the burner. The inlet vent must originate on the
same wall surface as the boiler outlet vent, if a direct venting system is used. The inlet hood
should be waterproof and include a bug and bird screen.
In cases where the boiler is installed in an area where exhaust, kitchen or bath ventilation
systems and fans exist, they may create unsatisfactory combustion or venting conditions.
Special consideration should be made for additional air.
All combustion air and ventilation requirements should meet local code and or NFPA
Standard 31 and NFPA 211.

VENTING REQUIREMENTS
3
C. COMBUSTION AIR SUPPLY WITH NO BAROMETRIC DAMPER
When no Barometric Damper is used Table 1 should be used to size the air inlet pipe to the
burner air housing if using a direct vent application.
Table 1
NFPA or OEM Burner specifications should take precedence where required.
PART II. VENTING REQUIREMENTS
Oil fired appliances shall be connected to flues or vents having sufficient draft at all times to
ensure safe and proper operation of the appliance.
When venting the MUNCHKIN OFB boilers, all installations should conform to all national,
local and state codes and authorities having jurisdiction.
When no local code is in effect NFPA-31 should be used as a reference, and baseline docu-
ment.
In addition, the design of chimney connectors, chimneys, power-venting systems and direct
vent systems should also conform to local and State codes, and good industry practice. In
lieu of local codes, NFPA-211 should be used as a reference.
BAROMETRIC DAMPER
The MUNCHKIN OFB boiler does not normally require a barometric damper, but, it may be
required when the draft in the venting system is stronger than required, and the burner is
incapable of operating against a high negative over-fire pressure.
Figure 1 NEUTRAL PRESSURE POINT ADJUSTER
A. NEUTRAL POINT PRESSURE ADJUSTER
In some cases the chimney may produce a draft that is too excessive and beyond the con-
trol of a draft regulator. The burner in use should be a high static or air-box type. Also, if you
have a mechanical draft device at or near the outlet, you may get flame detachment, smoky
fires, and puffbacks.
Firing Rate Range (gph) Chimney Connector Size
0.75 to 1.00 5” round or equivalent
1.00 to 1.50 6” round or equivalent
1.50 to 2.25 7” round or equivalent

4
The best way to correct this is to insure that you do not have more than -.02" of negative
water column draft at the breeching or outlet of the unit.
If you have an excess draft situation, the installation of a "neutral pressure point adjuster",
(see Figure 1, page 3) will be required.
The adjuster is a device that will reduce excessive draft and draft regulator flow. It is espe-
cially helpful with powered draft devices and excessive chimney draft situations. Both situ-
ations can cause flame problems, condensation and chimney connector damage.
• Start by cutting a piece of sheet metal as shown in Figure 1, page 3, to form the
adjuster.
• In detail 'A', page 3, start by making a cut about 1/3 diameter through the fluepipe.
• Insert the adjuster into the fluepipe, start the burner and set breeching draft for -.02"
W.C.
• When adjustment is complete, scribe adjuster with line around pipe, 'B'.
• Make a second line about 1" above pipe radius line.
• Trim off the excess stock as shown in 'C' and then slit the stock between the lines ver-
tically. Bend the segments in alternate directions.
• Replace the adjuster, start the burner and verify settings taken earlier.
• If unchanged, bend tabs against fluepipe, drawing 'D', and anchor in place with sheet
metal screws. Seal any joints with high temp silicone and the adjuster is completed.
The adjuster will reduce the velocity and strength of the draft currents and allow you to
make a permanent and safe adjuster that cannot be adjusted again.
NOTE: Before locking the adjuster in its final position, make sure that the final firing rate
has been set and that all draft settings have been made and are final.
B. ROOF CLEARANCES
Standard roof clearances apply. It is the responsibility of the installer to ensure they are ade-
quate.
C. HEAT EXTRACTORS
The MUNCHKIN OFB oil fired boiler is not approved for use with a heat extractor mounted
in the breeching or fluepipe.
PART III. NATURAL DRAFT APPLICATIONS
CAUTION
After placing the boiler within close proximity to the venting system, the
following basic guidelines should be observed that will prevent the
following conditions from occurring:
COMBUSTION AIR AND VENTILATION

MECHANICAL DRAFT APPLICATIONS
5
• Condensation of flue gasses.
• Positive outlet draft conditions.
• Reverse flow of fluegas during or after burner shutdown.
In addition, the following rules of good industry practice should be followed;
• Always try to keep chimney connector length to ten feet (10'), or less.
• The chimney connector must never be smaller than the boiler flue outlet, and
should be constructed of at least 24-gauge metal.
It is important to note that due to the high efficiency of the MUNCHKIN OFB boilers con-
densing temperatures in the chimney connector and venting system may be reached.
If condensing temperatures of below 250 °F NET are reached in the chimney connector, the
following precautions may have to be taken;
• Seal all joints in venting system with high temperature silicone or mastic.
• Verify quality of chimney and liner. If a masonry, brick, or block chimney is used, or
the existing tile liner is in poor condition, a chimney liner suitably rated, and listed
for oil may have to be installed.
PART IV. MECHANICAL DRAFT APPLICATIONS
When using the MUNCHKIN OFB boilers in a mechanical draft application, the following
basic guidelines should be observed according to the venting system in use. In addition, it
is strongly recommended that the applicable precautions for Natural Draft Applications be
used.
In addition to all of the pertinent information regarding Natural Draft Applications whenever
a Mechanical Draft Application is used, it should be installed using the following instructions
and Figure 2, page 6 as reference;
• The terminating vent hood, and the inlet air hood should be on the same wall sur-
face, and on the wall opposite from the prevailing wind wall, if possible.
• All of the air for combustion to the burner is supplied directly from outside of the
building or structure, following the suggested applications below.
• Not less than 12" above the total accumulated snow and level grade.
• Not less than 4' horizontally or below any window, door or air inlet, and also
not more than 1' above any of these openings.
• Not less than 3' above a powered air inlet device that is within 10'.
• Not less than 2' from any other building.
• At least 3' from any inside corner of a building.
WARNING
• NEVER connect the appliance into a chimney or liner serving an open fireplace.
• Inspect and clean chimney, and verify it is free of restrictions and obstructions.
• The chimney connector must always be properly supported.
• NEVER install a manual damper in the venting system.
• Chimney connectors should be free of as many 90° degree turns as possible, and
be pitched upwards towards the vent.

POWER VENTER APPLICATIONS
6
• At least 1' from any roof soffit or ridge vent.
• At least 7' above any public walkway.
• All of the vent construction should consist of suitable materials and terminate at an
approved stainless steel hood.
• All of the vent piping should be sealed from air leaks.
• The vent pipe bend radius is 12".
• Place metal strapping every 36" to support vent pipe and prevent it from sagging.
• Follow the national codes for the installation of oil burning equipment: in USA -
NFPA 31, in Canada - CAN/CSA-B139 and local regulations.
Figure 2
PART V. POWER VENTER APPLICATIONS
When using a power venter, all of the recommendations and instructions of the manufac-
turer of the power venter MUST be followed and the entire installation must conform to any
and all local, State, and National codes.
WARNING
Do not install vent terminals on prevailing wind wall side of structure.
Moisture and ice may form around terminal. Make sure the surface is in
good repair and protected from damage.

DIRECT VENT APPLICATIONS
7
PART VI. DIRECT VENT APPLICATIONS
When using MUNCHKIN OFB- Models 3MOFB, 4MOFB AND 5MOFB on 'sealed' or 'direct'
vented systems, they must be ordered from the factory with a Direct Vent System manu-
factured by Flex-L International, Inc. whose part numbers are at the end of this section.
Figure 3
In addition to all of the previous stated information regarding Natural Draft Applications and
Mechanical Draft Applications the following additional instructions for Direct Vent
Applications must be followed while referencing Figure 3;
• The maximum wall thickness should be no more than 14". Contact HEAT TRANS-
FER PRODUCTS, INC. for recommendations in case of a thicker wall.
• That the Heat Transfer Products, Inc. Flex-L System is not designed for common
venting. Use this for a single appliance only unless otherwise approved.
• Utilize an appliance adapter test port for combustion testing as required by Flex-L.
• Follow the national codes for the installation of oil burning equipment: in USA -
NFPA 31, in Canada - CAN/CSA-B139 and local regulations.
A. INSTALLING THE JOINT ASSEMBLY
1) Loosen the gear clamps attached to the adapter sleeve and slide the adapter sleeve over
the vent pipe, Figure 4 and Figure 5, page 8.
2) Pull the corrugated inner tube out of the vent pipe for easy access to insert the adapter.
3) Apply sealant around the corrugated end of the adapter.
4) Align the flat seams at the end of both corrugated tubes and insert the adapter into the
vent tube. Screw the adapter into the vent pipe with a counter-clockwise motion. The

DIRECT VENT APPLICATIONS
8
adapter should be fully inserted into the inner vent tube until it's tight. The seams of both
tubes must be aligned for ease of insertion. If the adapter does not completely screw into
the vent pipe, unscrew it and try again repeating Step 4 page 7.
5) Seal around edge of vent pipe inner tube.
6) Slide the adapter sleeve back onto adapter and tighten the gear clamps to complete the
connection.
7) If the vent requires cutting to length, a fine toothed hacksaw can be used. Remove any
burrs and flare out the end of the inner vent tube for easy installation of the adapter.
Figure 4
B. INSTALLING THE OUTSIDE TERMINAL
Using Figure 6 and Figure 7, page 9, com-
plete the following steps:
1) Determine the terminal location.
2) Cut 8-1/4" diameter hole through the wall
(slightly larger than the O.D. of the terminal).
3) Pull apart the inner and the outer terminal
sections.
4) Slide the outer wall plate over the outer
section of the terminal until it rests against
the bead.
5) From the outside of the building, insert the
outer section through the hole until it rests
against the wall.
6) From the inside of the building, slide the inner wall plate over the outer section and secure
using four (4) screws.
7) Position the outer section so the seam on the flue collar is on the top and the air intake on
the bottom. Secure the outer section by tightening the gear clamp around it. The gear clamp
is factory welded to the inner wall plate.
Figure 5

DIRECT VENT APPLICATIONS
9
8) Seal with a weatherproof sealant around the bead and edge of the outer wall plate to pre-
vent water from getting inside.
C. CONNECTIONS TO OUTSIDE TERMINAL
Using Figure 8 and Figure 9 complete the
following steps:
1) Slide the inner section over the vent pipe.
2) Connect the terminal adapter to the vent pipe
as per joint assembly.
3) Apply a bead of sealant around the terminal
flue collar.
4) Slide the appliance adapter over the flue
collar.
5) Tighten the gear clamp of the terminal
adapter around the flue collar.
6) Seal the seam in the adapter with sealant.
7) Slide the inner section over the outer section and secure by tightening the gear clamp.
8) Stretch the air intake flex to the desired length and slide over the air intake collar. Seal the
connection with the aluminum tape and secure using air intake clamp. Beaded end of the air
intake clamp should go first over the air intake collar.
9) Seal the gap between the vent pipe and the inner
section with silicone sealant.
D. CONNECTIONS TO APPLIANCE
Using Figure 10, Figure 11, Figure 12 and Figure 13
complete the following steps:
1) Connect the appliance adapter to the vent pipe as
per joint assembly.
2) Apply sealant around the appliance flue collar.
3) Slide the appliance adapter over the appliance flue
collar.
4) Tighten the gear clamp of the appliance adapter around the flue collar.
5) Seal the seam in the adapter with sealant.
6) Install burner air adapter.
7) Slide the end of air intake flex over the burner air adapter. Seal the connection with alu-
minum tape and secure using air intake clamp. Beaded end of the air intake clamp should
go first over burner air adapter.
8) A vacuum relief device may need to be installed if required by the appliance manufac-
turers' installation instructions.
Figure 6
Figure 7

MAINTENANCE
10
PART VII. MAINTENANCE
HEAT TRANSFER PRODUCTS, INC. and Flex-L International Inc recommends the entire heat-
ing system, including the appliance and vent, to be checked annually by a qualified heating
professional.
THE CERAFLEX VENT TERMINAL IS 0" CLEARANCE TO COMBUSTIBLES
Figure 8
Figure 9

MAINTENANCE
11
THE CERAFLEX INSULATED VENT PIPE IS 1" CLEARANCE TO COMBUSTIBLES
Figure 10 Figure 11
Figure 12 Figure 13

CERAFLEX “FLEX L” COMPONENTS LIST
12
PART VIII. CERAFLEX “FLEX L” COMPONENTS LIST:
Components - 4" Dia. System Part No.
CeraFlex Vent Pipe 10' Length CFV104
CeraFlex Vent Pipe 15' Length CFV154
CeraFlex Vent Pipe 20' Length CFV204
CeraFlex Appliance Adapter w/Pt 6"-4" CFAA64P
CeraFlex Terminal Adapter 4"-4" CFAT44
CeraFlex Vent Terminal 4" CFT4
CeraFlex Air Intake Flex 10'x4" L10-04
CeraFlex Air Intake Flex 15'x4" L15-04
CeraFlex Air Intake Flex 4" L20-04
CeraFlex Air Intake Clamp 4" CFGC4
Riello BF Air Adapter 3"-4" CFBA34-RL
CeraFlex Sealant 70ml XMM-SC5
NOTE: Other components may be available upon request.

FOR FURTHER TECHNICAL INFORMATION CONTACT:
HEAT TRANSFER PRODUCTS, Inc.
120 Braley Road
PO Box 429
East Freetown, MA 02717-0429
508-763-8071