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  • High Limit Vertical Mount Aquastat Relay<br>15°F Differential Product Image
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    High Limit Vertical Mount Aquastat Relay 15°F Differential L8148E1265 High Limit Vertical Mount Aquastat Relay 15°F Differential
    SKU: L8148E1265
    Brand: Honeywell
    (89)
    $209.99 each
    10
    Mon, Jun 15
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  • High or Low Limit & Circulator Strap-On Aquastat, 65°F to 200°F Product Image
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    High or Low Limit & Circulator Strap-On Aquastat, 65°F to 200°F L6006C1018 High or Low Limit & Circulator Strap-On Aquastat, 65°F to 200°F
    SKU: L6006C1018
    Brand: Honeywell
    (35)
    $95.69 each
    22
    Mon, Jun 15
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  • High Limit Horiz. Mount Aquastat Relay<br>8°F Differential Product Image
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    High Limit Horiz. Mount Aquastat Relay 8°F Differential L8148A1017 High Limit Horiz. Mount Aquastat Relay 8°F Differential
    SKU: L8148A1017
    Brand: Honeywell
    (77)
    $159.99 each
    221
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    221 Mon, Jun 15
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  • 140-240F AquaStat Relay w/ Vent Damper Connection Product Image
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    140-240F AquaStat Relay w/ Vent Damper Connection L8148E1257 140-240F AquaStat Relay w/ Vent Damper Connection
    SKU: L8148E1257
    Brand: Honeywell
    (48)
    $219.99 each
    1
    Mon, Jun 15
    32
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  • 120 Vac Oil<br>Electronic Aquastat Product Image
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    120 Vac Oil Electronic Aquastat L7224U1002 120 Vac Oil Electronic Aquastat
    SKU: L7224U1002
    Brand: Honeywell
    (37)
    $145.99 each
    11
    Mon, Jun 15
    249
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    238 Tue, Jun 16
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  • Aquastat Relay<br>8°F Differential Product Image
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    Aquastat Relay 8°F Differential L8148J1009 Aquastat Relay 8°F Differential
    SKU: L8148J1009
    Brand: Honeywell
    (52)
    $186.99 each
    11
    Mon, Jun 15
    184
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  • High or Low Limit Aquastat 100-240°F Range<br>5-30°F Adj Differential Product Image
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    High or Low Limit Aquastat 100-240°F Range 5-30°F Adj Differential L4006A2007 High or Low Limit Aquastat 100-240°F Range 5-30°F Adj Differential
    SKU: L4006A2007
    Brand: Honeywell
    (12)
    $94.99 each
    28
    Mon, Jun 15
    245
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    28 Mon, Jun 15
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  • High Limit Immersion Aquastat, 100-200&deg;F Range, 8&deg;F Differential Product Image
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    High Limit Immersion Aquastat, 100-200°F Range, 8°F Differential L4080B1352 High Limit Immersion Aquastat, 100-200°F Range, 8°F Differential
    SKU: L4080B1352
    Brand: Honeywell
    (4)
    $59.99 each
    59
    Mon, Jun 15
    279
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    59 Mon, Jun 15
    220 Tue, Jun 16
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  • 3/4" Aquastat Well Product Image
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    3/4" Aquastat Well 121371B 3/4" Aquastat Well
    SKU: 121371B
    Brand: Honeywell
    (13)
    $29.19 each
    76
    Mon, Jun 15
    366
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    76 Mon, Jun 15
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  • 1/2" Aquastat Well Product Image
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    1/2" Aquastat Well 121371A 1/2" Aquastat Well
    SKU: 121371A
    Brand: Honeywell
    (13)
    $26.99 each
    52
    Mon, Jun 15
    323
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    52 Mon, Jun 15
    271 Tue, Jun 16
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  • High/Low Limit Circulator Horiz. Mount Aquastat<br>100-240°F Product Image
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    High/Low Limit Circulator Horiz. Mount Aquastat 100-240°F L6006A1145 High/Low Limit Circulator Horiz. Mount Aquastat 100-240°F
    SKU: L6006A1145
    Brand: Honeywell
    (16)
    $103.99 each
    273
    Mon, Jun 15
    273
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    273 Mon, Jun 15
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  • High Limit Strap-On Aquastat, Manual Reset 100°F to 240°F Product Image
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    High Limit Strap-On Aquastat, Manual Reset 100°F to 240°F L4006H1004 High Limit Strap-On Aquastat, Manual Reset 100°F to 240°F
    SKU: L4006H1004
    Brand: Honeywell
    (6)
    $149.99 each
    31
    Mon, Jun 15
    260
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    31 Mon, Jun 15
    229 Tue, Jun 16
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  • High Limit Protection<br>Low Limit & Circulator Triple Aquastat Relay Product Image
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    High Limit Protection Low Limit & Circulator Triple Aquastat Relay L8124A1007 High Limit Protection Low Limit & Circulator Triple Aquastat Relay
    SKU: L8124A1007
    Brand: Honeywell
    (16)
    $218.99 each
    5
    Mon, Jun 15
    110
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  • High or Low Limit Remote Bulb Aquastat, 100-240°F<br>5-30°F Adj. Differential Product Image
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    High or Low Limit Remote Bulb Aquastat, 100-240°F 5-30°F Adj. Differential L4008A1015 High or Low Limit Remote Bulb Aquastat, 100-240°F 5-30°F Adj. Differential
    SKU: L4008A1015
    Brand: Honeywell
    (10)
    $116.99 each
    14
    Mon, Jun 15
    102
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  • High Limit, Manual Aquastat Controller<br>130°F to 270°F Product Image
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    High Limit, Manual Aquastat Controller 130°F to 270°F L4006E1000 High Limit, Manual Aquastat Controller 130°F to 270°F
    SKU: L4006E1000
    Brand: Honeywell
    (2)
    $104.99 each
    194
    Mon, Jun 15
    194
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    194 Mon, Jun 15
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  • Circulator Aquastat<br>5°F to 30°F Adj. Differential 100°F to 240°F Range Product Image
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    Circulator Aquastat 5°F to 30°F Adj. Differential 100°F to 240°F Range L4006B1163 Circulator Aquastat 5°F to 30°F Adj. Differential 100°F to 240°F Range
    SKU: L4006B1163
    Brand: Honeywell
    (8)
    $87.99 each
    1
    Mon, Jun 15
    31
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  • High/Low Limit Aquastat<br>40&#176;F to 180&#176;F Range Product Image
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    High/Low Limit Aquastat 40°F to 180°F Range L4006A1959 High/Low Limit Aquastat 40°F to 180°F Range
    SKU: L4006A1959
    Brand: Honeywell
    (9)
    $108.99 each
    17
    Mon, Jun 15
    154
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  • 3/4" Aquastat Well Product Image
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    3/4" Aquastat Well 121371B-OMI 3/4" Aquastat Well
    SKU: 121371B-OMI
    Brand: OMI
    (1)
    $11.99 each
    67
    Tue, Jun 16
    67
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    67 Tue, Jun 16
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  • 1/2" Aquastat Well Product Image
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    1/2" Aquastat Well 121371A-OMI 1/2" Aquastat Well
    SKU: 121371A-OMI
    Brand: OMI
    (2)
    $9.79 each
    6
    Mon, Jun 15
    96
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  • High Limit, Manual Reset Aquastat Controller<br>130&#176;F to 270&#176;F Product Image
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    High Limit, Manual Reset Aquastat Controller 130°F to 270°F L4008E1040 High Limit, Manual Reset Aquastat Controller 130°F to 270°F
    SKU: L4008E1040
    Brand: Honeywell
    (1)
    $105.99 each
    12
    Mon, Jun 15
    40
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  • High Limit Aquastat<br>130°F to 270°F Range<br>Manual Reset Product Image
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    High Limit Aquastat 130°F to 270°F Range Manual Reset L4006E1067 High Limit Aquastat 130°F to 270°F Range Manual Reset
    SKU: L4006E1067
    Brand: Honeywell
    (4)
    $149.99 each
    8
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    113
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  • High or Low Limit Aquastat 100-240&#176;F Range<br>5&#176;F to 30&#176;F Differential Product Image
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    High or Low Limit Aquastat 100-240°F Range 5°F to 30°F Differential L4006A1678 High or Low Limit Aquastat 100-240°F Range 5°F to 30°F Differential
    SKU: L4006A1678
    Brand: Honeywell
    (4)
    $109.99 each
    24
    Mon, Jun 15
    132
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  • Temperature Aquastat for "00" Series Circulators (95&#176;F to 115&#176;F) Product Image
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    Temperature Aquastat for "00" Series Circulators (95°F to 115°F) 563-2 Temperature Aquastat for "00" Series Circulators (95°F to 115°F)
    SKU: 563-2
    Brand: Taco
    (3)
    $29.79 each
    11
    Wed, Jun 17 – Thu, Jun 18
    11
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    11 Wed, Jun 17 – Thu, Jun 18
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  • High Limit Vertical Mount Aquastat Relay<br>15°F Differential Product Image
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    High Limit Vertical Mount Aquastat Relay 15°F Differential L8148E1299 High Limit Vertical Mount Aquastat Relay 15°F Differential
    SKU: L8148E1299
    Brand: Honeywell
    (13)
    $221.99 each
    6
    Mon, Jun 15
    179
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    173 Tue, Jun 16
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FAQs, Manuals & Videos

Resources

Videos

Articles

  • An aquastat is a device used to control water temperature in hydronic heating systems. It has both high and low limit temperature controls to prevent boilers from firing too frequently. Aquastats are a type of thermostat that senses the temperature of the water and activates or deactivates the burner by controlling the electrical circuit. The temperature of the water is maintained by the aquastat within its preset limits. When the thermostat demands heat, the heating mechanism activates and heat will be sent until the maximum temperature limit is reached. At that point, the mechanism will turn off. If the boiler's water temperature drops below the max temperature limit, the boiler will re-fire. The boiler will also re-fire when the boiler water temperature goes below a range around the low limit. This low limit is intended for tankless domestic hot water, ensuring that boiler water remains warm enough to heat domestic hot water.

    Aquastat wells are used in conjunction with aquastats. Immersion wells are used with Aquastat Temperature Controllers to hold the temperature sensing bulb in the controlled medium. They also prevent leakage of the controlled medium. Honeywell aquastat wells are popular and are available in 1/2" and 3/4" sizes.

    Our website offers a wide selection of Honeywell, White Rodgers, and Taco aquastats and wells for regulating the temperature of liquids in boilers, storage tanks, and other applications where temperature control is required.

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