15
B. Removing an Existing Boiler From a Common Chimney
 ReadthisonlyiftheCHGboilerisreplacinganexistingboilerthatisbeingremovedfromacommonchimney.
ThissectiondoesnotapplytotheinstallationofaCHGboiler.
Insomecases,whenanexistingboilerisremovedfromacommonchimney,thecommonventingsystemmay 
betoolargefortheremainingappliances.Atthetimeofremovalofanexistingboiler,thefollowingsteps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)Visuallyinspecttheventingsystemforpropersizeandhorizontalpitchanddeterminethereisno 
blockageorrestriction,leakage,corrosionandotherdeciencieswhichcouldcauseanunsafecondition.
(c)Insofaraspractical,closeallbuildingdoorsandwindowsandalldoorsbetweenthespaceinwhichall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commonventingsystem.Turnonanyexhaust
fans,suchasrangehoodsandbathroomexhausts,sotheywilloperateatmaximumspeed.Donotoperatea
summerexhaustfan.Closereplacedampers.
(d)Placeinoperationtheappliancebeinginspected.Followthelightinginstructions.Adjustthermostatsothe 
appliancewilloperatecontinuously.
(e)Testforspillageatthedrafthoodreliefopeningafter5minutesofmainburneroperation.Usetheameof 
amatchorcandle,orsmokefromacigarette,cigar,orpipe.
(f)Afterithasbeendeterminedthateachapplianceremainingconnectedtothecommonventingsystem 
properlyventswhentestedasoutlinedabove,returndoors,windows,exhaustfans,replacedampersand 
anyothergas-burningappliancestotheirpreviousconditionofuse.
(g)Anyimproperoperationofthecommonventingsystemshouldbecorrectedsotheinstallationconforms 
withtheNationalFuelGasCode,ANSIZ223.1.Whenre-sizinganyportionofthecommonventing
system,thecommonventingsystemshouldberesizedtoapproachtheminimumsizeasdeterminedusing 
theappropriatetablesinPart11oftheNationalFuelGasCode,ANSIZ223.1.
warNINg
NEVEr COmmON VENT a Chg bOIlEr wITh OThEr aPPlIaNCEs
CauTION
VENT SySTEMS MADE By BuRNHAM, HEAT FAB, PRoTECH, AND Z-FLEx RELy oN GASkETS
FoR PRoPER SEALING. WHEN THESE VENT SySTEMS ARE uSED, TAkE THE FoLLoWING
PRECAuTIoNS:
• MAkE SuRE THAT GASkET IS IN PoSITIoN AND uNDAMAGED IN THE FEMALE END oF THE
PIPE.
• MAkE SuRE THAT BoTH THE MALE AND FEMALE PIPES ARE FREE oF DAMAGE PRIoR To
assEmbly.
C. Vent / Intake System Assembly
1) GeneralAssemblyNotes:
a) Wheretheuseof“silicone”iscalledforinthefollowinginstructions,useGERTV106fortheventcollar.Air
inletpipingsectionsaresealedwithanygeneral-purposesiliconesealantsuchas GERTV102.PVCair
inletpipingsectionsareconnectedwithPVCcement.
b) Longitudinalweldedseamsshouldnotbeplacedatthebottomofhorizontalsectionsofexhaustpipe.
c) Donotdrillholesinventpipe.
d) Donotattempttomixventcomponentsofdifferentventsystemmanufacturers.
e) Insomecases,therearedifferencesbetweentheventsysteminstallationinstructionsinthismanualand
thoseintheventsystemmanufacturer’smanual.Wheresuchdifferencesexist,thismanualtakes 
precedenceovertheventsystemmanufacturer’smanual.