Specifications

Aquastat Controllers
194 customer.honeywell.com 70-6910
L8100 Aquastat® Controller
L8100A,B, and C are immersion type controllers for regulating and
limiting the tank temperature in water heaters. As the water
temperature rises past the setpoint, the controller switches off the
gas valve.
• Regulates temperature and provides energy cutoff (ECO) action on
a temperature rise past the setpoint.
• Includes a second sensing element that senses average water
temperature to minimize stacking.
• Fluid-filled element operates Micro Switch™ SPST snap-acting
switch.
• ECO switch interrupts the thermocouple circuit or main valve before
tank reaches 210 F (99 C) maximum temperature.
• Includes factory-installed immersion well on controller.
• Internal adjustment screw.
• Special switch terminal provides three-wire hookup from Aquastat®
controller to gas valve.
Dimensions in inches (millimeters)
Bulb Size: 3/8 in. (10 mm)
Differential Temperature: Controller: 5 F, fixed. Energy Cutoff Switch:
20 F, fixed. (Controller: 3 C fixed; Energy Cutoff Switch: 11 C fixed.)
Temperature Rating (ECO) Energy Cutoff: 190 F
Maximum Ambient Temperature: Maximum Tank: 210 F (Maximum
Tank: 99 C)
Operating Temperature Range: 100 F to 180 F (38 C to 82 C)
Electrical Ratings:
Millivolt:
2A maximum at 24 Vac.
Approvals:
American Gas Association IAS: Design Certified: Report Number 23-
11B
Underwriters Laboratories, Inc. UL Component Recognized: File No.
MP466, Guide No. MBPR2
1/2 OR 3/4 — 14 NPT
C
B
A
M4746
CONTROLLER WELL REMOTE WELL
A INSULATION DEPTH
B INSERTION DEPTH
C WELL DIAMETER
IN. MM
2-1/4
5
7/16
57
127
11
1-1/2 OR 2-1/2
3
7/16
38 OR 64
76
11
TANK WALL
IN. MM
Product Number Application
Capillary
Length Insulation Depth
Switching Action Mounting Includes(inch) (inch) (mm)
L8100B1037 High Limit 42 in. controller well: 2 1/4 in.
remote well: 1 1/2 or
2 1/2 in.
controller well: 57 mm,
remote well: 38 mm or
64 mm
SPST, contacts
break on
temperature rise.
Immersion
Well
—
L8100B1094 High Limit 54 in. controller well: 2 1/4 in.
remote well: 1 1/2 or
2 1/2 in.
controller well: 57 mm,
remote well: 38 mm or
64 mm
SPST, contacts
break on
temperature rise.
Immersion
Well
Two zinc plated wells
and one well clamp for
remote well.
L8100B1128 High Limit 39 in. 1 1/2 in. 38 mm SPST, contacts
break on
temperature rise.
Immersion
Well
—