Weil-McLain GV90+ Installation And Start-Up Manual page 2

GV90+ Series 2
oAs·FIRED WATER BOILER -
Boiler Manual
How
it
works •••
1 Integrated boiler control
The
integrated
boiler
control
(I BC)
responds to signals from the room thermostat, air
pressure
switdl,
i:nlet water sensor, boiler wa.ter temperature sensor and boiler lim it circuit
to operate
the
circulators,
gas
valve, igniter and blower. When a room thermostat caU s
for heat, the IBC starts the system circulator and blower.
The JBC runs the biO'\\•er
to
purge the boiler flue passages, then turns on the
igniter and
lets it warm up.
After igniter warm· up, the I DC opens the gas vah-e, rurns
the
igniter off, and checks for
flame. The flame
must
come on within 4 wconds or the
me
will shut down and
try
the
full cyde again.
W hen
the
room thermostat
is
satisfied. the IBC
turns
off
the
boiler components and
wai.ts
(or
the
next beat
call.
The
IBC indicator ligh.ts show nonnal sequence when the lights are on steady. When a
problem occurs, the JBC flashes combinations of lights which indicate the most bkely
reason for the problem..
Wh ile attempting to satisfy the heat demand, the control module monitors the
boiler
temperature changes via the temperature sensors and determines whether or not the
available hot water w.tll satisfy the demand, only running
the
ci:rculator. If additional
heat
is
needed, the sequence conti:nues.. When DHW (if
used)
caJJs for heat. sequence
above is bypassed.
2 Transformer
The control transformer reduces line vottage
to 24
volts for
the
gas
valve and limit ci:rcuit.
3 Blower
The blower pulls i:n ai:r and mixes it with gas
&om
the gas valve. The bla\\'et forces this
mixturt into lhe burner for comlxu:tion inside-
the-
boiler chamber.
4 Recuperator
The recupenttor
is
a stainless steel beat exchanger that increases boaer efficiency by ex·
trading additional beat &omthefluegaws, Return waterpasws through the recuperator
before entering the boiler.
5 Water temperatur e sensor
The
wat~r t~mptralur~
sensor provides a signal to
the
conrrol module to turn
off rhe
gas
valv~
if the
temprratur~
in the boiler goes
abo~
its setring. (The
circulator wlll conrinue to run as long as
there is a call
for heat.)
6 System circulator
The system circulator circulates water through the external (S)'Stem) piping, The flow
ra.te
ofthecirculator i:s controlled by
the
IBC, depending on the temperature
of
the water
entering the boiler .se<tion$. Pump mu.<n remain on boiler - do not remove.
7 Bypa .. circulator
The IBC operates the bypass circulator to mi.x hot water from the boiler outlet with
colder return
"' a ter
from the S)'Stem as needed to prevent condensation of flue gases in
the cast iron heat exchanger.
When
the
water returning to the boiler
Is
below I W F . the IBC regulate$
the
bypass ci:r·
culatorand system circulator flow rates to raise the
return
water temperature
up
to l40'"F
before it enters the cast iron sections, By balancing these flow rates. the IBC can protect
agai:n.st condensation in the cast iron heat exchanger e\'en if return water
Is
as low as 6Crf.
Pump mU$t remain o n boiler - do not rem m-e.
8 Air pre .. ure
switch
The
ai:r pressure switch signals
the
IBC.teUing the control whether air is moving through
the blower.
9 Return water temperature sensor
2
The
water temperatUI'e sensor monitors
the
temperature
of
the water entering
the
boiler
sectfons. The sensor sends this Information to the IBC. The IBC determines how much
to
adjust
the cirrulator flO\\' rates to provide at least 140'"P water to the cast iron beat
exchanger.
LEGEND
a
Supply to system> 1"' NPT
b
Return from
system,
I" NPT
c
Combustion
air
lnlet fitting -
3"' PVC connection
d
FJue outlet - 3"' PVC conntc·
tion
e
Gas vaJve - negative
p r~ssurt
regulated
gas
control
I
Pressure/temperature gauge
g
FJueway inspection port CO\'tr
h
Stnsor hose trap
Manual air vtnt
Relief vaJ\·t
k
Thermal
fuse-
a o ne· time fuse
device that shuts boiler off
if flue
te:mptrature exceeds irs strpoint
m
Condtnsate trap line -shipped
loose with boiler, field installed
n
Condensate d rain connection-
W'
PVC female
This boiler uses a negarive· prtssurt-
rtgulattd gas valve, ser for an outlet
pressure approximately -0. 20"' water
column.
00 NOT
set
rhe outlet
p r~ssurt
higher
than facto ry setting.
Pan number
550-142-783/1012