Honeywell L8124B, L8124C, L8124A, L8124G, L8124E Product Data

L8124A,B,C,E,G,L,M

Aquastat® Relays

PRODUCT DATA

GENERAL

These immersion type controllers are for use with forced
hydronic heating systems that include domestic hot water
service.

FEATURES

• L8124 Aquastat® Relays provide high limit, low limit,
and circulator control for maintaining boiler
temperatures.

• L8124 Aquastat Relays can provide multizone control
by using a separate circulator and R845 Relay for
each zone.

• All L8124 Aquastat Relays mount directly on the boiler.

• L8124E,G and L have large transformers and extra
terminals for supplying power to low voltage zone
valves.

• L8124M is for use in a wood-coal/gas-oil multifuel
heating system. Circulator is independently controlled
by the thermostat.

® U.S. Registered Trademark
Copyright © 2001 Honeywell • All Rights Reserved

Contents

General ............................................................................. 1

Features ........................................................................... 1

Specifications ................................................................... 2

Ordering Information ........................................................ 2

Installation ........................................................................ 5

Wiring ............................................................................... 7

Operation .......................................................................... 10

Setting And Checkout ....................................................... 10

Checkout .......................................................................... 14

Material Safety Data Sheet (MSDS) ................................. 14

60- 2061- 10

L8124A,B,C,E,G,L,M AQUASTAT® RELAYS

SPECIFICATIONS

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
calibrated under closely controlled conditions, and
some minor differences in performance can be
expected if those conditions are changed.

TRADELINE® Models

TRADELINE models are selected and packaged for ease of
handling, ease of stocking, and maximum replacement value.
TRADELINE model specifications are the same as those of
standard models except as noted in Table 1.

Tradeline Models Available L8124B,E,G,L Aquastat Relays

without well and spud.

Additional Features:

• Heat-conductive compound for better bulb response in
oversized well.

• Case can be vertically or horizontally mounted.

• Field-addable limit stops.

• TRADELINE pack with cross reference label and special
instructions.

Pressure Rating:

200 psi (1380 kPa) on outside of immersion well.
100 psi (690 kPa) on capsule if inserted directly.

Maximum Ambient Temperature:

Case: 150°F (66°C).

Sensing element: 265°F (129°C).

Thermostat Heat Anticipator Setting: 0.2A.

Low Limit:

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:

Setting: 130°F to 240°F, adjustable (54°C to 116°C).
Differential: 10°F, fixed (6°C).

Mounting Means: 1/2 or 3/4 in. taper pipe threaded.

Dimensions: See Fig. 1 and 2.

Sensing Element: 3/8 x 2-7/8 in (10 x 73 mm).

Insulation Depth: 1-1/2 or 3 in. (38 or 76 mm);

see Fig. 1 and 2.

Insertion Length: 3-3/8 in. (86 mm).

Approvals:

Underwriters Laboratories Inc.:

Listed (L8124 models with well): File No. MP466,

Guide No. MBPR.

Component Recognized (L8124 Models Without Well):

File No. MP466, Guide No. MBPR2.

Canadian Standards Association:

Component Recognized: File No. LR1620,

Guide No. 400-E-O.

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.

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 (check white pages of your phone directory).

2. Home and Building Control Customer Relations

Honeywell, 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.

60-2061—10 2

L8124A,B,C,E,G,L,M AQUASTAT® RELAYS

Table 1. Aquastat Relay models.

Electrical

Ratings

Burner
Circuit

Model

Number

Burner

Control

Circuit

Case Dimensions

Height Width Depth

in. mm in. mm in. mm

Can be

Used For

Multizone

With

Circulators

No. of V8043

Zone Valves

Powered

Without

Additional

a

Transformer

L8124A 120V 6-1/8 156 4-3/8 111 3-1/16 78 Yes — Same as

L8124A-G,L
circulator
rating

L8124B

b

6-1/8 156 4-3/8 111 3-1/16 78 — — 0.25A at 1/4

to 12 Vdc

L8124C 120V 4-3/8 111 6-1/8 156 3-1/16 78 Yes — Same as

L8124A-G,L
circulator
rating

L8124E 24V 6-1/8 156 4-3/8 111 3-1/16 78 Yes 2 1.25A at 24

Vac ; 3 0 VA
(total load)
B1-B2 TV-Z

L8124G 120V 6-1/8 156 4-3/8 111 3-1/16 78 — 2 Same as

L8124A-G,L
circulator
rating

L8124L 120V 4-3/8 111 6-1/8 156 3-1/16 78 Yes 2 Same as

L8124A-6,L
circulator
rating

L8124M 120V 4-3/8 111 6-1/8 156 3-1/16 78 Yes — Same as

L8124A

a

Multizone control can be provided by using a separate circulator and R845 Relay for each zone.

b

Contacts are not powered; they are rated for switching of millivoltage loads.

Circulat

or

Circuit

120 Vac:

7.4A (full
load);

44.4A
(locked
rotor)

240
Vac:3.7A
(full
load);

22.2A
(locked
rotor)

Mounting

Vertical

Vertical or
horizontal

Horizontal

Vertical or
horizontal

Horizontal

Replacement Aquastat Assemblies:

See Table 2 and Fig. 3 through 7.

Table 2. Replacement Aquastat assemblies.

Celsius (L8124A,

Model

L8124A-C,

Fahrenheit

1-1/2 in. or 3 in. (38

or 76 mm) insulation

125026AAE 125026BAC

100/220V Model Only)

1-1/2 in. or 3 in. (38

or 76 mm) insulation

E,G,L,M

3 60-2061—10

L8124A,B,C,E,G,L,M AQUASTAT® RELAYS

6
(

2-1/8 (54)

5

T

T

(VERTICAL
MOUNT)

4-5/16 (110)

-1/8

156)

3-1/8

(79)

1/8 (3)

1-1/4 (32) (HORIZONTAL
MOUNT—BOTTOM)

KNOCKOUTS FOR
1/2 (13) CONDUIT

3-3/8

(86)

1-1/4 (32)
(VERTICAL
MOUNT)

3-1/16 (78)
(HORIZONTAL
MOUNT)

Fig. 1. L8124 mounting dimensions in in. (mm).

CONTROL
MOUNT

FITS BOILER TAPPED HOLE

1/2 OR 3/4 IN. NPT

M892

VOLTAGE
BARRIER

TRANSFORMER
FOR THERMOSTA
CIRCUIT

DIFFERENTIAL
SETTING

CIRCULATOR
RELAY

LOW LIMIT
SETTING

HIGH LIMIT
SETTING

Fig. 3. Internal view of L8124A and C.

TRANSFORMER
FOR THERMOSTA
CIRCUIT

M8961

DIFFERENTIAL
SETTING

INSULATION
LENGTH 1-1/2
OR 3 IN.
(38 OR 76 MM)

INSERTION
LENGTH
3-3/8 IN.
(86 MM)

M1797

CIRCULATOR
RELAY

LOW LIMIT
SETTING

Fig. 2. Immersion well dimensions. (Refer

to form 68-0040, Wells and Fittings for

Temperature Controllers, to order well.)

Fig. 4. Internal view of L8124B.

HIGH LIMIT
SETTING

GROUND SCREW

M8964

60-2061—10 4

TRANSFORMER

T

T

T

FOR THERMOSTA
CIRCUIT

DIFFERENTIAL
SETTING

CIRCULATOR
RELAY

LOW LIMIT
SETTING

HIGH LIMIT
SETTING

L8124A,B,C,E,G,L,M AQUASTAT® RELAYS

GROUND SCREW

VOLTAGE
BARRIER

TRANSFORMER
FOR THERMOSTA
CIRCUIT

DIFFERENTIAL
SETTING

CIRCULATOR
RELAY

Fig. 5. Internal view of L8124E.

GROUND

HIGH LIMIT
SETTING

SCREW

Fig. 6. Internal view of L8124G and L.

GROUND SCREW

M8962

TRANSFORMER
FOR THERMOSTA
CIRCUIT

DIFFERENTIAL
SETTING

CIRCULATOR
RELAY

LOW LIMIT
SETTING

M8853

LOW LIMIT
SETTING

HIGH LIMIT
SETTING

Fig. 7. Internal view of L8124M.

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

Fire or Explosion Hazard.
Can cause severe injury, death or property
damage.

Product is for use only in a system with a pressure
relief valve.

M8963

WARNING

5 60-2061—10

Electrical Shock Hazard.
Can cause severe injury, death or property
damage.

Disconnect power supply before beginning installation
to prevent electrical shock or equipment damage.