irculator 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.
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 L8124A,B,C,E,G,L,M AQUASTAT® RELAYS
60-206110
2
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 CanadaHoneywell 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.
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. L8124A,B,C,E,G,L,M AQUASTAT® RELAYS
3
60-206110
Table 1. Aquastat Relay models.
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.
Replacement Aquastat Assemblies:
See Table 2 and Fig. 3 through 7.
Table 2. Replacement Aquastat assemblies.
Model
Number
Burner
Control
Circuit
Case Dimensions
Can be
Used For
Multizone
With
Circulators
a
No. of V8043
Zone Valves
Powered
Without
Additional
Transformer
Electrical
Ratings
Height
Width
Depth
in.
mm
in.
mm
in.
mm
Burner
Circuit
Circulat
or
Circuit
Mounting
L8124A 120V
6-1/8 156
4-3/8 111
3-1/16 78
Yes Same as
L8124A-G,L
circulator
rating
120 Vac:
7.4A (full
load);
44.4A
(locked
rotor)
Vertical
L8124B
b
6-1/8 156
4-3/8 111
3-1/16 78
0.25A at 1/4
to 12 Vdc
Vertical or
horizontal
L8124C 120V
4-3/8 111
6-1/8 156
3-1/16 78
Yes Same as
L8124A-G,L
circulator
rating
240
Vac:3.7A
(full
load);
22.2A
(locked
rotor)
Horizontal
L8124E 24V
6-1/8 156
4-3/8 111
3-1/16 78
Yes
2
1.25A at 24
Vac; 30 VA
(total load)
B1-B2 TV-Z
Vertical or
horizontal
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
Horizontal
Model
Fahrenheit
Celsius (L8124A,
100/220V Model Only)
1-1/2 in. or 3 in. (38
or 76 mm) insulation
1-1/2 in. or 3 in. (38
or 76 mm) insulation
L8124A-C,
E,G,L,M
125026AAE
125026BAC L8124A,B,C,E,G,L,M AQUASTAT® RELAYS
60-206110
4
Fig. 1. L8124 mounting dimensions in in. (mm).
Fig. 2. Immersion well dimensions. (Refer
to form 68-0040, Wells and Fittings for
Temperature Controllers, to order well.)
Fig. 3. Internal view of L8124A and C.
Fig. 4. Internal view of L8124B.
3-1/8
(79)
1/8 (3)
6-1/8
(156)
3-3/8
(86)
2-1/8 (54)
(VERTICAL
MOUNT)
1-1/4 (32) (HORIZONTAL
MOUNTBOTTOM)
KNOCKOUTS FOR
1/2 (13) CONDUIT
4-5/16 (110)
1-1/4 (32)
(VERTICAL
MOUNT)
3-1/16 (78)
(HORIZONTAL
MOUNT)
M8925
CONTROL
MOUNT
FITS BOILER TAPPED HOLE
1/2 OR 3/4 IN. NPT
INSULATION
LENGTH 1-1/2
OR 3 IN.
(38 OR 76 MM)
INSERTION
LENGTH
3-3/8 IN.
(86 MM)
M1797
M8961
VOLTAGE
BARRIER
TRANSFORMER
FOR THERMOSTAT
CIRCUIT
DIFFERENTIAL
SETTING
CIRCULATOR
RELAY
LOW LIMIT
SETTING
HIGH LIMIT
SETTING
M8964
TRANSFORMER
FOR THERMOSTAT
CIRCUIT
DIFFERENTIAL
SETTING
CIRCULATOR
RELAY
LOW LIMIT
SETTING
HIGH LIMIT
SETTING
GROUND SCREW L8124A,B,C,E,G,L,M AQUASTAT® RELAYS
5
60-206110
Fig. 5. Internal view of L8124E.
Fig. 6. Internal view of L8124G and L.
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.
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property
damage.
Disconnect power supply before beginning installation
to prevent electrical shock or equipment damage.
M8962
TRANSFORMER
FOR THERMOSTAT
CIRCUIT
DIFFERENTIAL
SETTING
CIRCULATOR
RELAY
LOW LIMIT
SETTING
HIGH LIMIT
SETTING
GROUND SCREW
M8853
DIFFERENTIAL
SETTING
LOW LIMIT
SETTING
GROUND
SCREW
HIGH LIMIT
SETTING
TRANSFORMER
FOR THERMOSTAT
CIRCUIT
CIRCULATOR
RELAY
M8963
VOLTAGE
BARRIER
TRANSFORMER
FOR THERMOSTAT
CIRCUIT
DIFFERENTIAL
SETTING
CIRCULATOR
RELAY
LOW LIMIT
SETTING
HIGH LIMIT
SETTING
GROUND SCREW L8124A,B,C,E,G,L,M AQUASTAT® RELAYS
60-206110
6
IMPORTANT
1. Terminals on these Aquastat relays are approved
only for copper wire.
2. Immersion well must snugly fit sensing element and
bulb must rest against bottom of well. Bend the
tubing, if necessary, to hold bulb against the bottom
of the well. Do not make a sharp bend in the tubing
that can produce a break in the tubing and cause
loss of fill. This condition will cause the high and low
limit controllers to be made continuously.
Mounting Standard Models
The boiler must be provided with a tapping that allows
horizontal mounting of the well. It should be located where
boiler water of average temperature can circulate around the
well.
To mount the L8124, proceed as follows:
1. Turn off all power and drain the boiler.
2. If no tapping is provided, prepare one that is properly
sized and threaded at the location selected.
3. Install the immersion well (ordered separately) in the
boiler tapping and tighten securely.
NOTE: Do not attempt to tighten the well using the case as a
handle.
4. Refill the boiler and check for water leakage.
5. Loosen, but do not remove, the clamp screw on the
bottom (L8124A,B,E,G) or on the top (L8124C,L,M)
of the case.
6. Insert the element in the well until it bottoms.
7. Fit the case onto the well so that the clamp on the case
slides over the flange on the well. Securely tighten the
clamp screw.
TRADELINE Models
IMPORTANT
Use the heat-conductive compound furnished with
the TRADELINE L8124 to obtain best thermal
response. Fold the plastic bag of compound
lengthwise and twist it gently. Snip off end and work
open end of the bag all the way into the well. Slowly
pull out the bag while firmly squeezing it to evenly
distribute the compound.
Position the mounting bracket on th