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Differential

Adjustable (33)
Fixed (22)
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Contacts Break on Temp Rise (27)
Open on Rise (3)
SPDT (8)
SPST (39)

Min Temp (F)

100°F (1)
40°F (1)
65°F (1)
95°F (1)
100°F (27)
110°F (10)
120°F (2)
130°F (9)
180°F (2)

Max Temp (F)

115°F (1)
135°F (1)
180°F (2)
200°F (5)
220°F (1)
240°F (37)
240°F (1)
270°F (7)
270°F (1)

Application

Accessory (11)
Circulator Control (16)
High Limit (48)
Low Limit (21)
Oil Aquastat Controller (1)
Strap-On (4)
Triple Aquastat Relay (5)

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(5)
(2)

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$15 to $20 (3)
$30 to $35 (1)
$35 to $40 (1)
$40 to $45 (4)
$45 to $50 (2)
$50 to $60 (9)
$60 to $70 (3)
$70 to $80 (1)
$80 to $90 (2)
$100 to $200 (21)

Boiler Aquastats

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Product Image of Circulator Aquastat, 100-240-Degree(F) range, 5-30-Degree(F) Adj Differential, L4006B1155
$191.79 each
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Product Image of High & Low Limit Aquastat, 10-Degree(F) Fixed, 10-25-Degree(F) Differential, L6081A1036
$331.50 each
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Product Image of Low Limit & Circulator Remote Bulb Aquastat, 100-240-Degree(F) range, 5-30-Degree Adj Differential, L6008A1192
$300.91 each
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Product Image of High Limit & Circulator Aquastat, 10-Degree(F) High Limit, 10-Degree(F) to 25-Degree(F) Low Limit Adj Differential, L4081B1047
$312.20 each
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Product Image of High Limit Aquastat, 100-200-Degree (F) range, Manual Reset, L4006E1125
$297.19 each
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Product Image of 1/2" Stainless Steel Aquastat Well
1/2" Stainless Steel Aquastat Well
SKU: 121371E
Resideo
SKU: 121371E
Brand: Resideo
(2)
$231.62 each
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Product Image of Fast Response Control w/ 100-240°F Range and 5-45°F Differential
$259.23 each
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Product Image of High or Low Limit & Circulator Aquastat, 100-240-Degree(F) range, 5-30-Degree(F) Adj Differential, L6006A1012
$252.26 each
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Product Image of High Limit, Manual Aquastat Controller w/ 130-Degree (F) to 270-Degree (F) Operating Temp, L4006E1109
$217.61 each
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Product Image of 1/2" Aquastat Well (3" Long), 123869A
1/2" Aquastat Well (3" Long), 123869A
SKU: 123869A
Resideo
SKU: 123869A
Brand: Resideo
(3)
$50.67 each
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Product Image of High Limit & Circulator Aquastat, 10-Degree (F) Differential, L4081B1096
$304.03 each
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Product Image of Circulator Aquastat, 100-240-Degree(F) range, 5-Degree(F) Differential, L4006B1007
$228.94 each
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Product Image of Remote Bulb Control w/ 5-45°F Adjustable Differential
$231.23 each
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Product Image of Flush Mount Sensor Assembly w/ 36" Lead, 50001464-004
Flush Mount Sensor Assembly w/ 36" Lead, 50001464-004
SKU: 50001464-004
Resideo
SKU: 50001464-004
Brand: Resideo
(1)
$59.99 each
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Product Image of Combo Protector Relay & Hydronic Heating Control w/ High Limit: 10F fixed, Low Limit/Circulator, Junction Box Mount (10F to 25F), R8182H1070
$1,122.09 each
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Product Image of Well Immersion Control w/ 100-240°F Range (Open On Rise)
$233.75 each
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Product Image of Strap-On Hydronic Temperature Control w/ 10 Degree Fixed Differential
$125.75 each
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Product Image of High or Low Limit Remote Bulb Aquastat, 130-270-Degree (F), 5-30-Degree (F) Adj Differential, L4008A1130
$344.61 each
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Product Image of Combination Protector Relay & Hydronic Heating Control w/ High Limit: 10 F fixed, Low Limit/Circulator (10F to 25F), R8182D1079
$1,100.14 each
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Product Image of High Limit Triple Vertical Mount Aquastat Relay, High = 10-Degree(F) Diff, Low = 10-25-Degree(F) Adj Differential, L8124G1020
$405.86 each
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Product Image of High Limit Aquastat, 130-270-Degree (F) range, Manual Reset, L4006E1091
$234.93 each
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Product Image of High Limit Triple Horizontal Mount Aquastat Relay, High = 10-Degree(F) Diff, Low = 10-25-Degree(F) Adj Differential, L8124L1011
$397.69 each
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Product Image of Copper Well Assembly w/ 3" Insertion, 123870A
$51.64 each
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Product Image of Immersion Well w/ 1/2" Shank (3-1/2" x 7/16")
$51.61 each
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Product Image of Aquastat Controller, Unit Pack, L4006G1006
Aquastat Controller, Unit Pack, L4006G1006
SKU: L4006G1006
Resideo
SKU: L4006G1006
Brand: Resideo
$158.93 each
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Product Image of Low Limit & Circulator Remote Bulb Aquastat, 100-200-Degree(F) range, 5-30-Degree Adj Differential, L6008A1242
$313.87 each
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Product Image of Copper Well Assembly w/ 3" Insertion, 3/8" Diameter, 1/2" NPT, 123872A
$58.46 each
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Product Image of Limit Control w/ manual reset, 135 F fixed range and 3" insertion, L4029E1011
$194.67 each
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Product Image of 1/2" Well w/ 1-13/16" Shank
1/2" Well w/ 1-13/16" Shank
SKU: F89-0211
White Rodgers
SKU: F89-0211
$41.81 each
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Product Image of Immersion Well w/ 1/2" Shank
Immersion Well w/ 1/2" Shank
SKU: F89-0148
White Rodgers
SKU: F89-0148
$55.56 each
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Product Image of Fast Response Direct Immersion Control w/ 100-240°F Range and 7-45°F Differential
$356.88 each
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Product Image of Sensor Assembly w/ 24" Lead, 32004955-003
Sensor Assembly w/ 24" Lead, 32004955-003
SKU: 32004955-003
Resideo
SKU: 32004955-003
Brand: Resideo
$77.17 each
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Product Image of 3/4" Well, 3-1/2" x 7/16" Bulb
$49.08 each
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Product Image of Copper Well Assembly w/ 3-3/4" Insertion
Copper Well Assembly w/ 3-3/4" Insertion
SKU: 112620AA
Resideo
SKU: 112620AA
Brand: Resideo
$153.73 each
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Product Image of High Limit, Manual Aquastat Controller w/ 130-Degree(F) to 270-Degree(F) Operating Temp, L4006E1042
$265.57 each
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Product Image of Outdoor Reset Module for L7224/L7248 Series 2 (Includes Outdoor Sensor), W8735S1000
$479.87 each
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Product Image of 1/2" Well Direct Mt to Control
$53.67 each
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Product Image of 3/4" Well w/ 1-13/16" Shank
3/4" Well w/ 1-13/16" Shank
SKU: F89-0213
White Rodgers
SKU: F89-0213
$39.93 each
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Product Image of Aquastat, L7224C1004/B
Aquastat, L7224C1004/B
SKU: L7224C1004/B
Honeywell
SKU: L7224C1004/B
Brand: Honeywell
$175.18 each
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Product Image of 1/2" Well for 1609,1629,2A23
1/2" Well for 1609,1629,2A23
SKU: F89-0027
White Rodgers
SKU: F89-0027
$34.91 each
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More About Aquastats & Wells
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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