Install Instructions

9. The air space clearance between the masonry chimney exterior and
combustible materials should be checked to verify that the chimney is in
accordance with the clearance specifi cations contained in the NFPA 211
Standard or other recognized major building codes, i.e., on an exterior
chimney clearance is 0” while on an interior chimney, clearance is 0”.
10. The Z-Flex Flexible Liner is intended for use as a chimney liner in masonry
or pre-fab metal chimneys for oil burning appliances listed for use with type
L vents, gas burning appliances equipped with draft hoods or listed with type
B gas vents or listed solid fuel pellet fi red appliances whose continuous gas
temperature does not exceed 570˚ F. The following list details only some
intended uses of “OS” chimney liner. If your appliance is not on this list
and you are not sure if it is appropriate to use with “OS” liner, contact the
appliance manufacturer prior to installation.
• Furnace
• Water heater
• Gas fi replace
• Boiler
11. Minimum and maximum clearance:
Maximum chimney height = 65 feet high
Minimum chimney height = 10 feet high
Minimum brick thickness = 3
1
⁄
2
inches thick.
12. Clearance from connectors to unprotected combustible material shall be in
accordance with the table below (ref: NPFA 211).
Minimum Clearance
Description of Appliance
inch (mm)
Gas appliances without draft hoods 18 (457)
Oil appliances 18 (457)
Unlisted gas appliances with draft hoods 9 (229)
Boilers and furnaces equipped with listed gas burners
and with draft hoods 9 (229)
Listed gas appliances with draft hoods 6 (152)
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