A
RUVG
MANUAL
28 of 35
June 14
13.
Open
all
manual
gas
valves
14.
Turn
power
on
at
disconnect
switch
15.
Set
thermostat
or
controller
to
its
highest
position
to
initiate
call
for
heat
and
maintain
operation
of
unit.
16.
Draft
inducer
will
run
for
a
15
second
pre
‐
purge
period.
17.
At
the
end
of
the
pre
‐
purge
the
direct
spark
will
be
energized
and
gas
safety
shutoff
valve
will
open
and
if
provided
the
flow
ratio
valve
will
move
to
the
light
off
position.
18.
There
is
up
to
a
10
second
trial
for
ignition
to
light
the
burner.
During
this
time
the
direct
spark
is
energized
and
the
gas
valve
is
open.
19.
Confirm
the
burner
has
ignited.
Check
the
appearance
of
the
main
burner
flame.
The
burner
flame
should
be
mostly
blue
in
color
and
well
defined
and
centered
at
the
tube.
A
distorted
flame,
yellow
tipping
of
natural
gas
flame
or
a
long
yellow
flame
on
propane
may
be
caused
by
lint
and
dirt
accumulation
inside
burner
or
at
burner
ports.
20.
When
the
sensing
probe
proves
the
flame,
it
de
‐
energizes
the
spark
igniter.
See
the
internal
wiring
diagram
for
the
type
of
flame
ignition
control
used.
21.
On
the
initial
start
‐
up
the
first
ignition
trial
may
be
unsuccessful
due
to
need
to
purge
air
from
manifold
at
start
‐
up.
If
the
gas
fails
to
ignite
or
the
flame
is
not
sensed
the
ignition
control
will
lock
out.
To
clear
the
lockout
turn
the
service
switch
off
for
5
minutes
then
retry.
22.
Confirm
gas
inlet
pressure
matches
unit
rating
plate
at
high
fire.
The
appliance
regulator
shall
be
adjusted
to
provide
the
manifold
pressure
specified
on
the
rating
plate.
23.
Once
the
heat
call
is
satisfied:
a.
Ignition
controller
is
de
‐
energized.
b.
Main
gas
valve
is
de
‐
energized.
c.
Make
sure
flame
is
out.
24.
After
the
combustion
has
been
checked,
bring
the
unit
to
high
fire
and
check
entire
manifold
for
gas
leaks.
25.
When
the
main
flame
is
established,
check
the
gas
manifold
pressure
at
the
test
point
nearest
the
burner
with
the
unit
operating
at
high
fire.
Check
the
name
plate
for
the
correct
manifold
pressure
and
adjust
the
appliance
regulator
if
necessary.
The
unit
inlet
gas
pressure
should
not
go
below
the
minimum
pressure
shown
on
the
nameplate
when
at
high
fire.
Ensure
that
the
temperature
rise
does
not
exceed
nameplate.
26.
Do
a
final
check
of
the
main
and
safety
shutoff
valves
and
pilot
valve
for
leakage
following
the
valve
