Instruction Manual

4
SETTING THE CONTROL
To set COLD START operation
Operates on call for heat only.

Low Temperature Limit
Make sure Low Temperature Limit is turned fully counter-
clockwise (OFF position).

Low Temperature Differential
No change is required.

High Temperature Limit
(
factory setting = 190°F)
Adjust setting until desired temperature is displayed.

High Temperature Differential
(
factory setting = 10°F)
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.
To set WARM START operation
Maintains temperature for domestic hot water.

Low Temperature Limit
Adjust setting until desired temperature is displayed.

Low Temperature Differential
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.

High Temperature Limit
(factory setting = 190°F)
Adjust setting until desired temperature is displayed.

High Temperature Differential
(factory setting = 10°F)
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.
WARM START
(maintains temperature for domestic hot water)
Low Limit Switch = ON
COLD START
Low Limit Switch = OFF
Example
High Limit = 180°
Differential = 10°
On a call for heat, the burner will
shut off at 180° and restart at
170° (180°-10°). The circulator
will run as long as there is a call
for heat.
High Temperature Limit
(Adjustable 100° to 220°F)
De-energizes burner at HIGH
LIMIT setting
High Temperature Limit
(Adjustable 100° to 220°F)
De-energizes burner at HIGH
LIMIT setting
High Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the HIGH
LIMIT DIFFERENTIAL set point
High Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the HIGH
LIMIT DIFFERENTIAL set point
Low Temperature Limit
(Adjustable 110° to 200°F)
De-energizes burner at LOW
LIMIT setting
Low Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the LOW
LIMIT DIFFERENTIAL set point
Example
High Limit = 180°
Differential = 10°
On a call for heat, the burner will
shut off at 180° and restart at
170° (180°-10°). The circulator
will run as long as there is a call
for heat.
Example
Low Limit = 150°
Differential = 10°
When there is no call for heat,
the burner fires at 140°
(150°-10°) to maintain boiler
temperature. Burner shuts off
at 150°.
NOTE: To prioritize domestic hot
water the HydroStat control will
not allow the circulator to
operate at any time the
temperature is below the low
limit setting.
OPERATION
Dynamic
Display
W
ater Temperature
and Real Time
Verification of
S
etting Adjustments.
All Settings are
Displayed Every
T
ime Control is
Powered Up
Low Temperature
Limit Setting
(
OFF or 110°-200°F)
F
actory OFF
L
ow Temperature
Differential Setting
(10°-30°F)
Factory 10°F
High Temperature
Limit Setting
(
100°-220°F)
F
actory 190°F
D
iagnostic LEDs
H
igh Temperature
Differential Setting
(10°-30°F)
Factory 10°F




NOTE: Be careful not to select overlapping temperature settings.
For example: If the HIGH TEMPERATURE LIMIT is set at
190°F with a HIGH TEMPERATURE DIFFERENTIAL set at 20°F,
then the LOW TEMPERATURE LIMIT needs to be set at 170°F
(190°F - 20°F = 170°F) or below.
IMPORTANT: To prevent flue gas condensation and reduce fatigue
caused by thermal cycling on conventional (non-condensing) boilers,
both HIGH and LOW LIMIT set points should be 150°F or above
(Limit Setting - Differential Setting ≥ 150°F). Boiler manufacturerʼs
temperature requirements supercede these recommendations.