One Stage Boiler Control 253
D 253
- Data Brochure
05/97
The One Stage Boiler Control 253 is a microprocessor-based control designed to regulate the sup-
ply water temperature from a single boiler based on the outdoor temperature. To avoid boiler short
cycling and large temperature swings, the 253 is able to continuously adjust the boiler differential.
The 253 includes functions such as Warm Weather Shut Down (WWSD), Minimum Boiler setting, and
a Starting Temperature setting. The control has a digital, liquid crystal display (LCD) that normally
displays the Boiler Supply temperature, but can display other temperatures and settings.
Control Strategy . . . . . . . . . . . .
pg. 1
Testing the Control . . . . . . . pg. 6
Sequence of Operation . . . . . . . pg. 2
Error Messages. . . . . . . . . . . pg. 7
Installation . . . . . . . . . . . . . . . . .
pg. 3
Technical Data . . . . . . . . . . . pg. 8
Settings . . . . . . . . . . . . . . . . . . .
pg. 4
Limited Warranty . . . . . . . . . pg. 8
Input
24 V (ac)
Power Supply
Input
Outdoor Sensor
Included
Output
Boiler
Input
Boiler Sensor
Included
Item
4
Boiler
5
6
T
1
H1
1461
PRGM
F C
WWSD
24 V 50/60 Hz 3 VA
120 V (ac) 5 A 1/6 hp
pilot duty 240 VA
Power:
Boiler Relay:
Mar 97
31000265
- displays control settings
- displays hundreds of hours of use
- displays hours of use
Press & Hold:
Item
One Stage Boiler
Control 253
2
3
Com
Sen
Boil
Sen
Out
Sen
No power
7
8
Power
R+ C-
NRTL /C
LR 58223
R
USE
(hours)
Minimum Boiler
Differential
Curve
Boiler Supply
Target Boiler
Starting Temp.
H. Dem
Boiler
OUTDOOR
Signal wiring must be
rated at least 300V
Input
Heat Demand
Made in Canada
Control Strategy
OUTDOOR RESET
In order to properly control a hot water heating system, the heat supplied
to the building must equal the heat lost by the building.
• The heat supplied to a building is proportional to the temperature of the
supply water and the surface area of the heating element. A small surface
area such as baseboard radiators requires a higher water temperature
than a larger surface area such as radiant floors.
• The heat lost from a building is dependent on the outdoor temperature,
as well as other factors. As the outdoor temperature drops, the building
heat loss increases.
Constant
Room Temperature
Outdoor
Temperature
Drop
Heat
Loss
Increase
WWSD
Boiler Supply
Target Boiler
Starting Temp.
Minimum Boiler
Differential
Curve
H. Dem
Boiler
R
Use
(hours)
One Stage Boiler
Control 253
Item
NRTL/C
LR 58223
F
