2
!
CAUTION
Indicates an imminently hazardous situation
which, if not avoided, may result in injury or
property damage.
!
WARNING
Indicates an imminently hazardous situation
which, if not avoided, may result in death,
serious injury or substantial property damage.
!
DANGER
Indicates an imminently hazardous situation
which, if not avoided, WILL result in death,
serious injury or substantial property damage.
SaftEy SymbolS
Following symbols are used throughout this manual
to notify reader of potential hazards of varying risk
levels.
TABLE of conTEnTs
Safety Symbols ...........................................2
Warnings .....................................................2
Introduction .................................................3
Product Description .......................................3
Voltage Rating Tables ....................................4
Installation Procedure ...................................5
Design of Water Circulating System ................6
Connecting Supply and Return Piping ..............6
Connecting Electrical Power Supply .................8
Wiring Diagrams ......................................... 11
Thermostat Installation ............................... 15
Startup and Seasonal Maintenance ............... 15
Troubleshooting .......................................... 16
Maintenance ............................................. 17
Parts List - 2 Element Electric Boilers ........... 18
Parts List - 4 Element Electric Boilers ............ 19
Additional Wiring Diagrams .......................... 20
Modular Boiler Piping .................................. 23
Troubleshooting .......................................... 24
"AT" Series Boiler Dimensions ...................... 27
Homeowner's Reference Table ...................... 28
insTALLATion mAnuAL And opErATing insTrucTions
KEEP THIS MANUAL NEAR BOILER
RETAIN FOR FUTURE REFERENCE
NOTICE
Owner: Installation and service of this boiler
must be performed by qualified installer.
Installer: Leave all instructions with the boiler
for future reference.
When this product is installed in the
Commonwealth of Massachusetts installation
must be performed by licensed plumber or
licensed gas fitter.*
* In other areas, consult authority having
jurisdiction.
!
WARNING
BOILER SIzINg IS CRUCIAL. The maximum
hourly heat loss for each heated space should
be calculated in accordance with procedures
describes in The Hydronics Institute (I=B=R)
manual H-22 (Heat Loss Calculation guide),
or by any other method which is suitable for
local conditions, provided the results are in
substantial agreement. Select appropriate
boiler based on accurate heat loss calculation.
DO NOT OVERSIzE BOILER, AS SIzINg IS
CRITICAL FOR IN-FLOOR RADIANT HEAT
APPLICATIONS.
Keep boiler area clear and free from
combustible materials, gasoline and other
flammable vapors and liquids.
Do not obstruct air openings to boiler room.
Modification, substitution or elimination
of factory equipped, supplied or specified
components may result in property damage,
personal injury or loss of life.
NOTICE
Read the following instructions completely
before installing!!
NOTICE
Indicates information which should be
followed to ensure proper installation and
operation.