Install Instructions

28
VIII. OPERATION (continued)
E. CHANGING THE ADJUSTABLE PARAMETERS
To adjust parameters such as High Limit Setpoint and
High Limit Differential:
1. Access the adjustment mode by pressing and
holding the Up ñ, Down ò, and “I” keys
simultaneously for three (3) seconds. This
procedure is intended to discourage unauthorized
changes or accidental changes to limit settings.
2. Press the "
I" key to display available Adjustment
Mode options. Select an option.
Adjustment Mode Options
HL_
140-220°F Adjust High Limit Setting
dF_
10-30°F Adjust High Limit Differential
Or_
0-10 minutes Circulator Overrun Time
PP_
2-20 minutes Circulator Pre-purge Time
St_
140-180°F Start Temperature
Pt_
On or off Priority time
dh_
dh or tt2 DH Terminal Function
rst
Reset Lockout
f-C
F or C Select degrees F or C Mode
bac
Back to Operating Mode
3. Press the Up ñ and Down ò keys to adjust the
displayed item to the desired value.
4. To return to the normal operating mode from the
Adjustment Mode, when the "bAc” option is
displayed, press either the Up ñ or Down ò key. If
no keys are pressed, after ve (5) minutes the
control will automatically return to the Operating
Mode.
F. MORE INFORMATION ABOUT ADJUSTABLE
PARAMETERS
1. High Limit (HL_)
The control is factory programmed with a High
Limit Setpoint of 180°F. The burner turns "off"
when the boiler water temperature (bt) is above this
value. The High Limit setpoint is adjustable
between 140° and 220°F. The Operating Setpoint
(SP) will equal the High Limit Setpoint.
2. Differential (df_)
The control is factory programmed with a
Differential of 15°F. The Differential is the number
of degrees the boiler temperature must decrease
below the Operating Setpoint before the boiler can
restart. The differential is adjustable between 10°
through 30°F.
3. Circulator Overrun Time (OR_)
The control is factory programmed with a Circulator
Overrun Time of 0 minutes. Circulator Overrun
Time (also called “circulator off delay” or
“circulator post purge”) continues circulator
operation after a call for heat has ended, sending
excess heat from the boiler into the system. Ensure
system piping and zone panel settings allow water
ow to the priority zone after the call for heat ends.
The Circulator Overrun Time is adjustable between
0 through 10 minutes.
4. Circulator Pre-purge Time (PP_)
When the boiler is warm (boiler water temperature
higher than 140°F (adjustable using Start
Temperature parameter)) and there is a thermostat
call for heat, the system circulator is started and
boiler ring is delayed Circulator Pre-purge minutes.
If the temperature drops below 140°F or there is a
DHW call for heat the boiler is started without
delay. Additionally, the boiler is started without
delay if the thermostat call for heat is initiated when
the boiler water temperature is less than 140°F. This
feature helps save energy by satisfying home heating
needs with residual boiler heat rather than cycling
the boiler. The Circulator Pre-purge time has a
factory setting of 2 minutes and is eld adjustable
between 2 and 20 minutes. Refer to Table 6.
Call for
Heat
Source
DHW
Terminal
Selection
Boiler
Temperature
Burner Status
TT = on - <140 Start with no delay
TT = on - >140 Start after 2 minute delay
DHW = on tt2 <140 Start with no delay
DHW = on tt2 >140 Start after 2 minute delay
DHW = on dh <140 Start with no delay
DHW = on dh >140 Start with no delay
Table 6: Circulator Pre-purge Time example,
(PP_ = 2 minutes)
5. Start Temperature (St_)
Amount of “Heat available” is calculated by taking
the difference between measured boiler water
temperature and the Start Temperature setting.
Useful “Heat Available” is dependent on the type of
heating emitter installed in the home. Heat emitters
require a certain minimum temperature to operate
effectively. Our default settings reect cast iron
radiators. Fan Coils may require a start temperature
setting of 180°F or 160°F before providing heat to
the home. The Start Temperature has a factory
setting of 140°F and is eld adjustable between
140°F and 180°F.
6. Priority Time (Pt_)
When the Priority Time parameter is set to “on” and
Domestic Hot Water (DHW) call for heat is “on” the
DHW demand will take “Priority” over home
heating demand. During Priority Time the system
circulator will be forced “off”. Priority Time ends
and the system circulator is released to service home
heating demand when Domestic Hot Water call for
heat is over. When Priority Time parameter is set to
“Off” the DHW call for heat does not force “off” the
system circulator. The Priority Time has a factory
setting of “On” and is eld adjustable between “On”
and “Off” Refer to Table 7.