Installation
20
│
Page
PRESSURE
RELIEF
VALVE
The
T
‐
H2
‐
DV/T
‐
H2
‐
OS
has
a
high
‐
temperature
shut
off
switch
built
in
as
a
standard
safety
feature
(called
a
Hi
‐
Limit
switch)
therefore
a
“pressure
only”
relief
valve
is
required.
1.
This
unit
does
not
come
with
an
approved
pressure
relief
valve.
2.
An
approved
pressure
relief
valve
must
be
installed
on
the
hot
water
outlet.
3.
The
pressure
relief
valve
must
conform
to
ANSI
Z21.22
or
CAN
1
‐
4.4
and
installation
must
follow
local
code.
4.
The
discharge
capacity
must
be
at
least
199,000
BTU/h.
5.
The
pressure
relief
valve
needs
to
be
rated
for
a
maximum
of
150
psi.
6.
The
discharge
piping
for
the
pressure
relief
valve
must
be
directed
so
that
the
hot
water
cannot
splash
on
anyone
or
on
nearby
equipment.
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
due
to
a
defective
thermal
expansion
tank
or
defective
pressure
relief
valve.
9.
The
pressure
relief
valve
must
be
manually
operated
periodically
to
check
for
correct
operation.
CONDENSATE
DRAIN
•
The
T
‐
H2
‐
DV/T
‐
H2
‐
OS
does
not
include
a
built
‐
in
condensate
neutralizer
cartridge
for
reducing
the
pH
level
of
condensate
water.
If
local
codes
dictate
that
condensate
must
be
neutralized
prior
to
drainage,
a
condensate
neutralizer
must
be
installed.
As
an
option,
Takagi
offers
the
TH
‐
NT01
Neutralizer
assembly
(sold
separately).
•
In
the
absence
of
applicable
local
codes
and
regulations,
TAKAGI
recommends
that
condensate
be
disposed
of
into
a
standard
drain.
Connect
a
drain
tube
from
the
condensate
drain
port
(shown
below)
located
on
the
bottom
of
the
T
‐
H2
‐
DV/T
‐
H2
‐
OS
to
a
standard
drain.
Pressure
Relief
Valve
Hot
outlet
Cold
inlet
Gas
As
Close
as
Possible
•
Follow
all
code
requirements
of
the
local
authority
on
condensate
neutralizers
and
whether
or
not
they
are
required
for
the
installation.
Condensate drain
port