60-2553—3 2
L8151A
SPECIFICATIONS • INSTALLATION • ORDERING INFORMATION
Specification
IMPORTANT: The specifications given in this publication
do not include normal manufacturing tolerances.
Therefore, this unit may not exactly match the listed
specifications. Also, this product is tested and cali-
brated under closely controlled conditions, and some
minor differences in performance can be expected if
those conditions are changed.
MODEL: L8151A Triple Aquastat® Relay for remote bulb
control of hydronic heating systems that include domestic
hot water.
ELECTRICAL RATINGS:
Power Supply: 120 Vac, 60 Hz; 220 Vac, 50 Hz and
240 Vac, 60 Hz operation.
Contact Ratings (A): See Table 1.
TABLE 1—CONTACT RATINGS.
MAXIMUM AMBIENT TEMPERATURE: 150°F (66°C)
at case. 265°F (130°C) at sensing element.
PRESSURE RATING: 200 psi (1380 kPa) on outside of
immersion well.
THERMOSTAT HEAT ANTICIPATOR SETTING: 0.2A.
LOW LIMIT (Fig. 2):
Function: Maintains water temperature at setting during
thermostat off periods.
Setting: 110°F to 220°F adjustable (43°C to 104°C).
Differential: 10°F to 25°F adjustable (6°C to 14°C).
HIGH LIMIT (Fig. 2):
Function: Opens burner circuit if water temperature reaches
high limit setting.
Setting: 130°F to 240°F adjustable (54°C to 116°C).
Differential: 10°F fixed (6°C).
MOUNTING MEANS: Mounting lugs on back of case.
DIMENSIONS: See Fig. 1.
SENSING ELEMENT: 3/8 x 2-7/8 in. (10 x 73 mm).
CAPILLARY LENGTH: 36 in. (914 mm), armored
capillary.
UNDERWRITERS LABORATORIES INC. LISTED: File
No. MP466, Guide No. MBPR2.
Installation
WHEN INSTALLING THIS PRODUCT...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazardous
condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for your
application.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.

WARNING

CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY OR DEATH.
Product is for use only in a system with a pressure
relief valve.
120 Vac 240 Vac
Full Load 7.4 3.7
Locked Rotor 44.4 22.2
MAXIMUM POWER CONSUMPTION: 8W at 120 Vac,
60 Hz.
Ordering Information
When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the Tradeline®
Catalog or price sheets for complete ordering number, or specify—
1. Order number. 3. Order additional system components and system
2. Accessories, if desired. accessories separately.
If you have additional questions, need further information, or would like to comment on our products or services, please write or phone:
1. Your local Home and Building Control Sales Office (please check the white pages of your phone directory).
2. Home and Building Control Customer Logistics
Honeywell Inc., 1885 Douglas Drive North
Minneapolis, Minnesota 55422-4386
In Canada—Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9. International Sales and
Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France, Germany, Japan, Mexico,
Netherlands, Spain, Taiwan, United Kingdom, U.S.A.