Install Instructions
43
IX. 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 13.
5. Start Temperature (St_)
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 13: Circulator Pre-purge Time example,
(PP_ = 2 minutes)
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 reect 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 14.