4Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
1 Prepare boiler location continued
Failuretofollowallinstructionscanresultinuegas
spillageandcarbonmonoxideemissions,causing
severe personal injury or death.
When removing boiler from existing common vent system:
Atthetimeofremovalofanexistingboiler,thefollowingsteps
shall be followed with each appliance remaining connected to
the common venting system placed in operation, while the other
appliances remaining connected to the common venting system
are not in operation.
a. Seal any unused openings in the common venting system.
b. Visuallyinspecttheventingsystemforpropersizeandhori-
zontalpitchanddeterminethereisnoblockageorrestriction,
leakage,corrosionorotherdeciencieswhichcouldcausean
unsafecondition.
c. Testventsystem—Insofarasispractical,closeallbuilding
doors and windows and all doors between the space in which
the appliances remaining connected to the common venting
system are located and other spaces of the building.Turn
on clothes dryers and any appliance not connected to the
commonventingsystem.Turnonanyexhaustfans,suchas
rangehoodsandbathroomexhausts,sotheywilloperateat
maximumspeed.Donotoperateasummerexhaustfan.Close
fireplace dampers.
d. Place in operation the appliance being inspected.Follow the
lighting/operatinginstructions.Adjustthermostatsoappliance
will operate continuously.
e. Testforspillageatdrafthoodreliefopeningafter5minutesof
mainburneroperation.Usetheameofamatchorcandle.
f. Afterithasbeendeterminedthateachapplianceremaining
connectedtothecommonventingsystemproperly ventswhen
testedasoutlinedabove,returndoors,windows,exhaustfans,
fireplace dampers, and any other gas-burning appliance to
theirpreviousconditionsofuse.
Any improper operation of common venting system should be
corrected so the installation conforms with the National Fuel
GasCode,ANSIZ223.1–latestedition.Correctbyresizingto
approach the minimum size as determined using the appropriate
tablesinPart11ofthatcode.Canadianinstallationsmustcomply
withB149.1orB149.2InstallationCode.
Chimney draft vent requirements
1. Venting must be installed according to Part 7, Venting of
Equipment,ofNationalFuelGasCode,ANSIZ223.1-latest
editionandapplicablebuildingcodes.Canadianinstallations
mustcomplywithB149.1orB149.2InstallationCodes.
2. Chimneyorventtermination:
• Achimney,oranyventotherthanaTypeBventwithlisted
ventcap,mustextendatleast3feetabovethehighest
pointwhereitpassesthrougharoofofabuilding,andat
least2feethigherthananyportionofabuildingwithina
horizontaldistanceof10feet.
• TypeBventswithlistedcapsmayterminateasinFigure2
ifnocloserthan8feetfromaverticalwallorsimilarob-
struction.
• Otherwise,Type B ventsmustterminate at least2 feet
abovetheroofpenetrationandatleast2feethigherthan
anyportionofabuildingwithin10feet.
3. Alinedchimneyispreferredandmustbeusedwhenrequired
bylocal, state,provincialand national codes,laws,regulations
and ordinances. Vitreous tile linings with joints that prevent
retentionofmoistureandliningsmadeofnoncorrosivemateri-
alsarebest.Adviceforueconnectionsandchimneylinings
canbeobtainedfromlocalgasutility.TypeBdouble-wallmetal
vent pipe or single-wall vent pipe may be used as a liner.
4. Cold masonrychimneys,alsoknownas outside chimneys,
typicallyhaveoneormorewallsexposedtooutsideair.
When any atmospheric gas-fired boiler with automatic vent
damperisventedthroughthistypeofchimney,thepotential
existsforcondensationtooccur.Condensationcandamage
amasonrychimney.Manufacturerrecommendsthefollowing
to prevent possible damage.
a. Linechimneywithcorrosion-resistantmetallinersuchas
AL29-4C®single-wallstainlesssteelorB-vent.Sizeliner
perNationalFuelGasCodeANSIZ223.1–latestedition.
b. Provide drain trap to remove any condensate.
5. Where two or more gas appliances vent into a common chim-
neyorvent,equivalentareashouldbeatleastequaltoareaof
ventoutletonlargestapplianceplus50percentofventoutlet
areaofadditionalappliance.
Direct exhaust venting (Category III) — DO NOT
COMMON venttheGWIinadirectexhaustsystem
(CategoryIII).Connectingmorethanoneappliance
toadirectexhaustsystemwillcauseuegasspill-
ageorappliancemalfunction,resultinginpossible
severepersonalinjury,deathorsubstantial property
damage.
Inspect existing chimney before installing boiler.
Failure to clean or replace perforated pipe or tile
lining will cause severe personal injury or death.
Vent system
GWI boilers can be either chimney draft vented
or direct-exhaust vented. See pages 7 to 12 for
detailed installation instructions.
Ifyouareremovinganexistingboilerfromashared
ventingsystemandthenewGWIboilerwillnotshare
theventsystem(allowedonlywhenchimneydraft
venting),youmusttesteachremainingappliance
individuallytoverifytheventsystemstilloperates
adequately.Followguidelinesbelow.
Figure 2 Terminations with Type B vent tted with listed
cap, provided vent is at least 8 feet from any
vertical wall or similar obstruction.
