Installation Manual
Installation
20│Page
PRESSURERELIEFVALVE
TheT‐H2‐DV/T‐H2‐OShasahigh‐temperatureshutoffswitchbuiltinasastandardsafetyfeature(called
aHi‐Limitswitch)thereforea“pressureonly”reliefvalveisrequired.
1. Thisunitdoesnotcomewithanapprovedpressurereliefvalve.
2. Anapprovedpressurerelief
valvemustbeinstalledonthehotwateroutlet.
3. Thepressurereliefvalvemustconform to
ANSIZ21.22orCAN1‐4.4andinstallation
mustfollowlocalcode.
4. The discharge capacity must be at
least199,000BTU/h.
5. The pressure relief valve needs to be
ratedforamaximum
of150psi.
6. Thedischarg epipingforthepressurereliefvalvemust
be directed so that the hot water cannot splash on
anyoneoronnearbyequipment.
7. Attach the discharge tube to the pressure relief valve and run the end of the tube to within 6"
from the
floor. This discharge tube must allow free and complete drainage without any
restrictions.
8. If the pressure relief valve installed on the T‐H2‐DV/T‐H2‐OS discharges periodically, this may be
duetoadefectivethermalexpansiontankordefectivepressurereliefvalve.
9. Thepressurereliefvalvemustbe
manuallyoperatedperiodicallytocheckforcorrectoperation.
CONDENSATEDRAIN
• TheT‐H2‐DV/T‐H2‐OSdoesnotincludeabuilt‐incondensateneutra lizer cartridgeforreducingthe
pHlevelofcondensatewater.Iflocalcodesdictatethatcondensatemustbeneutralizedpriorto
drainage,acondensateneutralizermustbeinstalled.Asanoption,TakagiofferstheTH‐NT01
Neutralizer
assembly(soldseparately).
• Intheabsenceofapplicablelocalcodesandregulations,TAKAGIrecommendsthatcondensatebe
disposedofintoastandarddrain.Connectadraintubefromthecondensatedrainport(shown
below)locatedonthebottomoftheT‐H2‐DV/T‐H2‐OStoastandarddrain.
Pressure
ReliefValve
Hot
outle
t
Cold
inle
t
Gas
AsCloseas
Possible
• Follow all code requirements
of the local authority on
condensate neutralizers and
whether or not they are
requiredfortheinstallation.
Condensate drainport