2-1
BOILER SYSTEMS AND OPERATION
SL 20-115 MODULATING GAS BOILER
2.0 bOILER SYSTEMS AND OPERATION
general
residential sl series modulating boilers are designed to service three separate,
directly piped heating loads using different pre-selected water temperatures and
heat regulation routines. external controls can extend applications.
The control is outfitted to provide for outdoor reset, set point regulation and DHW.
The design objective is DHW plus radiant floor and baseboard space heating,
each operable at a unique temperature.
While the three load “channels” are shipped pre-programmed with default values,
they can each be programmed with dHW, set-point control or outdoor reset
parameters
(see Section 2.7 Set Up and Load Definition).
the strategy is to
deliver high temperature water, as required by most indirect dHW tanks on the
market, and by finned tube baseboards, but default to the lowest possible boiler
supply temperature to maximize efficiency. The SL modulating series boilers can
handle supply temperatures within the range 34°F to 180°F.
Control
the control unit provides overall management of boiler operations, including:
1.
Power-up / set-up / boiler state machine (standby / heat call management etc).
2.
Burner, pumps (p external) and/or zone valve management.
3.
temperature and throttle operation.
4.
Maintenance of a service log with diagnostics.
5.
2 way communications.
operating and historical data may be accessed at any time, using the log and
Advanced Settings fields, available using the permanently lit LCD screen.
See
below.
data includes the following:
•
ignition counter
•
time records, including burn time by load and the throttle duty cycle
•
error log
user interFaCe
2.3.1 Keypad Functions
A five button keypad is provided for intuitive navigation around the screen. The
four outer keys are used to move the cursor up or down, and side to side. the
centre button is used to make selections and confirm inputs. The left hand key
is also used to back-step to the previous screen; multiple key stokes are used to
withdraw back to the operating status screen.
2.1
WARNING
If the boiler can become
exposed to fluid temperatures
below 34°F (1°C), a method of
protection to prevent freezing
of condensate should be
employed. Contact the factory
for further information.
2.2
2.3
