TwinTemp
Description
of
Operation
and
Sequence
of
Operation
Technical
Description
of
Operation
‐
The
TwinTemp
systems
provide
quiet
space
heating
utilizing
liquid
to
air
blowers
or
radiant
devices,
while
producing
a
continuous
supply
of
hot
water.
Its
Variflame
gas
modulation
enables
it
to
use
a
very
small
tank
and
still
maintain
efficiency
without
rapid
burner
cycling.
This
greatly
reduces
startup
time
and
standby
heat
loss.
Unlike
its
diesel
counterparts
the
TwinTemp
has
an
instant
on
burner
and
modulates
the
gas
flow
on
a
4
‐
1
ratio.
A
copper
heat
exchanger
inside
the
tank
of
heated
antifreeze
in
used
to
indirectly
heat
the
potable
water.
This
method
is
not
only
efficient,
but
will
extend
the
life
of
the
critical
heat
exchange
elements,
tank
and
circulating
pumps.
Sequence
of
Operation
The
power
and
propane
are
turned
on
to
the
TwinTemp
.
If
the
Tank
thermostat
senses
low
tank
temperature
(below
190°
F),
it
will
send
12
vdc
power
to
the
green
control
board
and
Pump
1
(rear)
pump
.
Note
‐
the
Junior
has
one
zone
pump
and
the
TwinTemp
‐
2
has
2
zone
pumps.
Anti
‐
freeze
starts
to
circulate
from
the
bottom
of
the
tank
,
through
Pump
1
,
to
the
burner
heat
exchanger
,
out
to
Zone
1
blowers
and
back
to
tank
.
Simultaneously,
the
control
board
powers
the
power
vent
relay
which
activates
the
power
vent
and
fluing
is
proofed
by
the
pressure
switch
via
the
¼”
hose.
The
pressure
switch
sends
12
VDC
to
the
ignition
board
(if
flue
is
blocked,
burner
will
not
light).
The
solenoid
gas
valve
is
energized
and
a
spark
is
effected
to
the
igniter
probe
over
burner
via
the
yellow
ignition
wire.
The
flame
is
proofed
via
the
same
igniter
element
and
yellow
wire.
Gas
flow
is
adjusted
by
the
gas
modulating
valve
based
on
antifreeze
temperature.
Temperature
readings
are
taken
twice
per
second
by
the
T
‐
Mid
Thermistor
.
As
set
temperature
(about
190°
F)
is
approached,
the
gas
flow
is
reduced
as
much
as
70%
by
reducing
the
voltage
to
the
gas
modulating
valve
until
set
temperature
is
achieved
and
the
burner
goes
off.
When
a
hot
water
tap
is
opened,
cold
water
enters
the
copper
tank
heat
exchanger
imbedded
in
the
tank
and
the
heat
transfer
takes
place.
The
hot
water
exits
the
tank
coil
through
a
tempering
valve
that
can
be
set
to
any
temperature
between
100°
‐
145°.
As
the
tank
cools,
the
burner
cycle
starts
again
when
the
tank
thermostat
senses
the
tank
is
getting
cold.
If
the
zone
1
room
thermostat
senses
low
room
temperature,
it
sends
power
to
the
zone’s
relay
that
then
powers
pump
1
,
control
board
and
the
zone
blowers
through
the
160
degree
tank
switch.
When
the
zone
2
(
TwinTemp
‐
2
only)
thermostat
calls
for
heat
the
zone
2
relay
sends
power
to
the
pump
2
and
the
blowers
in
zone
2
are
activated.
The
burner
will
be
activated
by
the
tank
thermostat
as
above
if
the
antifreeze
temperature
falls
below
set
temperature.
The
blower
thermostat
switch
will
turn
off
the
Zone
1
blowers
if
tank
temperature
drops
below
160°
F.
or
will
keep
blowers
off
until
tank
temperature
reaches
160
‐
170
degrees
on
cold
start.
NOTE:
The
bold
orange
terms
are
identified
and
pictured
in
the
following
pages.
