7
220
1.50 1.50 1.50 1.50 1.75 1.75 1.75 2.00 2.00 2.25 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50
215
1.25 1.50 1.50 1.50 1.50 1.75 1.75 1.75 2.00 2.25 2.25 2.50 2.50 2.50 2.50 2.50 2.50 2.50
210
1.25 1.25 1.50 1.50 1.50 1.50 1.50 1.75 2.00 2.00 2.25 2.50 2.50 2.50 2.50 2.50 2.50 2.50
205
1.25 1.25 1.25 1.50 1.50 1.50 1.50 1.75 1.75 2.00 2.25 2.25 2.50 2.50 2.50 2.50 2.50 2.50
200
1.25 1.25 1.25 1.50 1.50 1.50 1.50 1.75 1.75 2.00 2.00 2.25 2.50 2.50 2.50 2.50 2.50 2.50
195
1.00 1.25 1.25 1.25 1.50 1.50 1.50 1.50 1.75 1.75 2.00 2.25 2.25 2.50 2.50 2.50 2.50 2.50
190
1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.50 1.75 1.75 2.00 2.00 2.25 2.50 2.50 2.50 2.50 2.50
185
1.00 1.00 1.00 1.25 1.25 1.25 1.25 1.50 1.50 1.75 1.75 2.00 2.25 2.50 2.50 2.50 2.50 2.50
180
1.00 1.00 1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.50 1.75 2.00 2.00 2.25 2.50 2.50 2.50 2.50
175
1.00 1.00 1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.50 1.75 1.75 2.00 2.25 2.50 2.50 2.50 2.50
170
1.00 1.00 1.00 1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.50 1.75 1.75 2.00 2.25 2.50 2.50 2.50
165
0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.25 1.25 1.50 1.50 1.50 1.75 2.00 2.25 2.50 2.50 2.50
160
0.75 0.75 0.75 1.00 1.00 1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.75 1.75 2.00 2.25 2.50 2.50
155
0.75 0.75 0.75 0.75 1.00 1.00 1.00 1.00 1.25 1.25 1.25 1.50 1.50 1.75 2.00 2.25 2.50 2.50
150
0.75 0.75 0.75 0.75 0.75 1.00 1.00 1.00 1.00 1.25 1.25 1.50 1.50 1.75 1.75 2.00 2.50 2.50
145
0.75 0.75 0.75 0.75 0.75 0.75 0.75 1.00 1.00 1.00 1.25 1.25 1.50 1.50 1.75 2.00 2.25 2.50
140
0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 1.00 1.00 1.00 1.25 1.25 1.50 1.50 1.75 2.00 2.50
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
RESET RATIO CHART
O U T D O O R D E S I G N T E M P E R A T U R E
BOILER
TEMPERA
T
URE
STEP 6 – SETTING THE HYDROSTAT CONTROL – continued
To set the desired warm weather shutdown temperature:
Press and hold the TEST/SETTING BUTTON and simultaneously adjust the
ECONOMY dial to the desired setting. To turn the feature off – which will allow space
heating regardless of outdoor temperature – press and hold the TEST/SETTING
BUTTON and simultaneously turn the ECONOMY dial fully counter-clockwise.
Release the TEST/SETTING BUTTON. Be sure to reset the ECONOMY dial to the
correct setting. Any time the outdoor temp exceeds the WWSD setpoint, the display
will toggle boiler temperature (8 seconds), outdoor temperature (2 seconds), and OFF
(2 seconds).
SETTING THE OUTDOOR RESET
The outdoor reset will regulate the boiler’s temperature based on the temperature
outside. On cold days, the boiler will run at higher temperatures to meet the heating
load in the house. On warmer days, the boiler will run cooler to save energy while
still meeting the heating needs of the house. The HydroStat control uses a Reset
Ratio to calculate and maintain the proper boiler temperature.
To set the desired outdoor Reset Ratio:
1. Determine the Reset Ratio using the table below:
a. Locate the Outdoor Design Temperature for the system on the bottom of
the Reset Ratio Chart below. Round down to the next lowest number.
b. Locate the Boiler Design Temperature (supply temperature needed to meet
heating load at the Outdoor Design Temperature) on the left of the Reset
Ratio Chart below.
2. Adjust the ECONOMY dial on the HydroStat control to the Reset Ratio
determined by the intersection of a. and b. above.
Example: For a house located in Springfield MA (Design Temperature of
0°F) with baseboard heat (that was sized for the house based on the 180°F
baseboard rating), the reset ratio is 1.50.
Refer to the HydroStat instructions for other control settings.
