Ultra Boiler Manual

Part number 550-100-440/0122
32
  

Temperature settings — You must ensure that the
U-Control is set for the proper water temperatures for
the system. Excessive water temperature can cause sig-
nicant property damage in some applications.
Multi-temperature systems — If the heating system
includes circuits that require lower temperature water
(radiant slab circuits, for example) as well as higher
temperature circuits (DHW, nned tube baseboard, etc.),
it is recommended to protect low-temperature circuits
with limit controls that are wired to a U-Control external
limit circuit. Failure to provide regulation can result in
substantial property damage.
Figure 35 U-Control sequence of operation

e U-Control is fully programmable to meet system requirements, allow-
ing supply water regulation for up to three dierent systems.
U-Control features include:

Blower speed modulation to control the Ultra boiler’s ring rate.

Advanced PID response to anticipate system needs based on response
to heat input.

Graphic and robust text display for ease of operation monitoring and
troubleshooting.

Preset operating parameters for typical heating systems (nned tube
baseboard, radiant oor, DHW, and others), including target tempera-
tures, reset curves and circulator assignments.

Control of up to three circulators (boiler circulator plus two others),
assignable for each of the three possible inputs.

Programmable priority assignments for the heat inputs.

Integral outdoor reset option, with reset curves matched to the system
type selected.

Multiple boiler/heat source sequencing or modulation.

Built-in 0–10 VDC signal generator to allow parallel modulation of
multiple boilers; also capable of accepting 0–10 VDC input.

Dual sensors for boiler outlet temperature and ue temperature, pro-
viding redundant protection.

Integral low water protection (by monitoring boiler heat exchanger
temperature).

Boiler is shipped with an outdoor sensor and strap-on system supply
and return sensors.

1. Figure35 is a summary of the operating sequence for the U-Control.
2. e symbols shown appear in the display as the U-Control cycles the
boiler.
3. e wrench symbol appears when a scheduled maintenance date ar-
rives. is informs the homeowner to call the contractor for service.
4. e exclamation mark symbol appears when a problem has been
detected.
Display Control action (also see Figure36,page33)
POWER
UP
y Check the boiler model listed on the power-up
screen. If it is not correct, turn o the boiler. See
Figure115,page102 to change setting.
y When power is turned on, the screen lists sen-
sors that are detected. If any sensor is not listed,
m
ake sure it is connected correctly. Turn o
power and restart.
Standby
y Standby — no calls for heat
y Toggles through no dots, 1 dot, 2 dots, then
3dots while in standby (wrench symbol will
show instead if maintenance is needed)
Blower on
y Call for heat detected
y Display on with BLUE light (space heating) or
PURPLE light (DHW)
y Start min/max on timers if more than one system
is calling — highest priority starts rst
y Start circulators for this priority setup
y Calculate target temp — If sensor temp is below
target temp, begin ring sequence
y Blower to ignition speed for prepurge
y Multiple boilers/heat sources only — Start
additional-heat timer — type 1 boiler starts
immediately; type 2 activates other heat source
immediately, but doesn’t start unless the timer
times out; type 3 (LEAD boiler) starts immedi
-
ately and sends 0–10 VDC signal to others aer
t
imer times out; type 4 receives signal from
LEAD boiler and starts immediately (and starts
timer for the next boiler, if programmed)
Ignition on
y Aer prepurge times out, begin ignition cycle
y Activate gas valve and ignition spark
y Continue ignition spark for ignition period
y Turn o spark and use electrode to check for
ame signal
Space
heating
y Flame detected
y Hold boiler at low re for 1 minute
y Release boiler to modulation
y NOTE: If ame is not detected, the gas valve
is turned o, blower turns on (postpurge), and
control starts cycle again. Aer 5 failures, the
control waits 60 minutes, then tries again.
y If priority timer times out, switch to next priority
and start priority timer
y If demand satised, go to postpurge
DHW
heating
y Flame detected
y Release boiler to modulation immediately
y NOTE: If ame is not detected, the gas valve
is turned o, blower turns on (postpurge), and
control starts cycle again. Aer 5 failures, the
control waits 60 minutes, then tries again.
y If priority timer times out, switch to next priority
and start priority timer
y If demand satised, go to postpurge
Blower on
y Demand satised (temperature reaches target
temperature or limit setting)
y Gas valve o
y Blower to ignition speed for postpurge
y Return to standby aer purge
Maintenance
y Display turns RED, toggling between graphic
screen and maintenance screen (occurs when
maintenance schedule timer times out)
y Will show during standby only
y Boiler operates as normal
Error/fault
y Display turns RED due to error or limit event
y Flashing display means lockout condition —
display toggles between three screens as in
Figure124,page117.
WWSD
y Warm weather shutdown — the boiler will not
be allowed to re if the outside temperature is
greater than the WWSD setting.