Honeywell L4189A User Manual
Controllers, Application, Features
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PRODUCT DATA
68-0061—1
L4188A,B; L4189A,B; L6188A-C;
L6189A-C Aquastat
®
Controllers
APPLICATION
Aquastat
®
Controllers are bulb-type providing operating or
limit control of water temperature in hot water heating systems
and water heaters.
FEATURES
• L4188 and L4189 provide spst switching for high and
low limit control.
• L6188 and L6189 provide spst switching for low limit
and circulator control.
• L4188, L6188 models are direct-mounted.
• L4189, L6189 models are remote bulb.
• Diaphragm-operated switch breaks on temperature
rise (spst and normally closed spdt contacts).
• Compact controller case for application flexibility.
• 3/16 in. diameter bulb for faster response.
• All models available with or without setting knob.
Models without knob are adjusted with screwdriver.
• Choice of manual or auto reset. Auto reset models
available with fixed or adjustable differential.
• 1/4 in. male quick-connects standard; combination
screw and 1/4 in. quick-connects available.
• Field adjustable high or low limit stop available.
• Bracket for surface mounting available on remote bulb
models.
• Capillary on remote bulb models available in several
lengths.
• Immersion well with 1/2 in. NPT spud available as
accessory.
Direct Mount with
Setting Knob
Contents
Application.........................................................................
1
Features ............................................................................
1
Specifications ....................................................................
2
Ordering Information .........................................................
2
Installation .........................................................................
4
Wiring ................................................................................
6
Operation...........................................................................
7
Adjustments.......................................................................
7
Checkout ...........................................................................
8
Remote Bulb with
Screwdriver Slot