Pros, Join Our TradeMaster Program!
  • RB-24E, GuardDog Electronic <br>24V LWCO (Water) Product Image
    Add to List
    Add to List
    RB-24E, GuardDog Electronic 24V LWCO (Water) 144692 RB-24E, GuardDog Electronic 24V LWCO (Water)
    SKU: 144692
    Brand: Mcdonnell & Miller
    (8)
    $84.99 each
    9
    Mon, Feb 1
    9
    QtyArrives
    9 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • RB-122E, GuardDog Electronic<br> 120V LWCO (Water) Product Image
    Add to List
    Add to List
    RB-122E, GuardDog Electronic 120V LWCO (Water) 144676 RB-122E, GuardDog Electronic 120V LWCO (Water)
    SKU: 144676
    Brand: Mcdonnell & Miller
    (6)
    $90.18 each
    Mon, Feb 22 – Mon, Mar 1
    Arrives
    Mon, Feb 22 – Mon, Mar 1
    Questions? Call 1-888-757-4774 or LiveChat Img Chat Us
    Add to List
  • 150S-HD, Head Assembly for 150 series<br>(Snap Switch) Product Image
    Add to List
    Add to List
    150S-HD, Head Assembly for 150 series (Snap Switch) 173003 150S-HD, Head Assembly for 150 series (Snap Switch)
    SKU: 173003
    Brand: Mcdonnell & Miller
    (10)
    $482.99 each
    252
    Mon, Feb 1
    252
    QtyArrives
    252 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 67, Float Type<br>Low Water Cutoff (Steam) Product Image
    Add to List
    Add to List
    67, Float Type Low Water Cutoff (Steam) 149400 67, Float Type Low Water Cutoff (Steam)
    SKU: 149400
    Brand: Mcdonnell & Miller
    (25)
    $266.99 each
    129
    Mon, Feb 1
    129
    QtyArrives
    129 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 120V Electronic Auto Reset LWCO, (Water)<br>Electrical Knock-outs: 4 Product Image
    Add to List
    Add to List
    120V Electronic Auto Reset LWCO, (Water) Electrical Knock-outs: 4 LTA1203S-2 120V Electronic Auto Reset LWCO, (Water) Electrical Knock-outs: 4
    SKU: LTA1203S-2
    Brand: Taco
    (12)
    $77.19 each
    82
    Mon, Feb 1
    304
    QtyArrives
    82 Mon, Feb 1
    222 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • Model 3250-Plus Fuel Smart Hydrostat for Oil Boilers (Temperature Limit, LWCO, & Boiler Reset Control) Product Image
    Add to List
    Add to List
    Model 3250-Plus Fuel Smart Hydrostat for Oil Boilers (Temperature Limit, LWCO, & Boiler Reset Control) 48-3250 Model 3250-Plus Fuel Smart Hydrostat for Oil Boilers (Temperature Limit, LWCO, & Boiler Reset Control)
    SKU: 48-3250
    Brand: Hydrolevel
    (12)
    $156.61 each
    78
    Mon, Feb 1
    78
    QtyArrives
    78 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 751P-MT-120, GuardDog Electronic manual reset LWCO<br>w/ Probe (Water) Product Image
    Add to List
    Add to List
    751P-MT-120, GuardDog Electronic manual reset LWCO w/ Probe (Water) 176234 751P-MT-120, GuardDog Electronic manual reset LWCO w/ Probe (Water)
    SKU: 176234
    Brand: Mcdonnell & Miller
    (4)
    $160.99 each
    5
    Mon, Feb 1
    5
    QtyArrives
    5 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 150-14H, Gasket for 150 Product Image
    Add to List
    Add to List
    150-14H, Gasket for 150 325600 150-14H, Gasket for 150
    SKU: 325600
    Brand: Mcdonnell & Miller
    $6.14 each
    294
    Mon, Feb 1
    294
    QtyArrives
    294 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • Safgard 5500 LWCO w/ Manual Reset & Test Button/Light - 120V Product Image
    Add to List
    Add to List
    Safgard 5500 LWCO w/ Manual Reset & Test Button/Light - 120V 45-550 Safgard 5500 LWCO w/ Manual Reset & Test Button/Light - 120V
    SKU: 45-550
    Brand: Hydrolevel
    (10)
    $195.13 each
    148
    Mon, Feb 1
    182
    QtyArrives
    148 Mon, Feb 1
    34 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • Safgard 1100 LWCO w/ Auto Reset & Burner Circuit Test Button - 24V Product Image
    Add to List
    Add to List
    Safgard 1100 LWCO w/ Auto Reset & Burner Circuit Test Button - 24V 45-1100 Safgard 1100 LWCO w/ Auto Reset & Burner Circuit Test Button - 24V
    SKU: 45-1100
    Brand: Hydrolevel
    (12)
    $79.91 each
    94
    Mon, Feb 1
    156
    QtyArrives
    94 Mon, Feb 1
    62 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • 24V Electronic LWCO (Water) 1" Probe Product Image
    Add to List
    Add to List
    24V Electronic LWCO (Water) 1" Probe LTR0243T-1 24V Electronic LWCO (Water) 1" Probe
    SKU: LTR0243T-1
    Brand: Taco
    (3)
    $84.99 each
    80
    Mon, Feb 1
    82
    QtyArrives
    80 Mon, Feb 1
    2 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • PSE802-24, Electronic 24V Low Water Cutoff with Auto Reset (Steam) Product Image
    Add to List
    Add to List
    PSE802-24, Electronic 24V Low Water Cutoff with Auto Reset (Steam) 153927-LWCO PSE802-24, Electronic 24V Low Water Cutoff with Auto Reset (Steam)
    SKU: 153927-LWCO
    Brand: Mcdonnell & Miller
    (5)
    $159.99 each
    43
    Mon, Feb 1
    43
    QtyArrives
    43 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • EL1214, 3/4" NPT Standard Ceramic Probe (2-7/8" ID) Product Image
    Add to List
    Add to List
    EL1214, 3/4" NPT Standard Ceramic Probe (2-7/8" ID) 45-214 EL1214, 3/4" NPT Standard Ceramic Probe (2-7/8" ID)
    SKU: 45-214
    Brand: Hydrolevel
    (6)
    $47.92 each
    129
    Mon, Feb 1
    129
    QtyArrives
    129 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • Model 3200-Plus Fuel Smart Hydrostat for Gas Boilers (Temperature Limit, LWCO, & Boiler Reset Control) Product Image
    Add to List
    Add to List
    Model 3200-Plus Fuel Smart Hydrostat for Gas Boilers (Temperature Limit, LWCO, & Boiler Reset Control) 48-3200 Model 3200-Plus Fuel Smart Hydrostat for Gas Boilers (Temperature Limit, LWCO, & Boiler Reset Control)
    SKU: 48-3200
    Brand: Hydrolevel
    (10)
    $147.62 each
    95
    Mon, Feb 1
    126
    QtyArrives
    95 Mon, Feb 1
    31 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • Safgard 1150 LWCO w/ Auto Reset & Burner Circuit Test Button -120V  Product Image
    Add to List
    Add to List
    Safgard 1150 LWCO w/ Auto Reset & Burner Circuit Test Button -120V 45-1150 Safgard 1150 LWCO w/ Auto Reset & Burner Circuit Test Button -120V
    SKU: 45-1150
    Brand: Hydrolevel
    (12)
    $88.09 each
    102
    Mon, Feb 1
    124
    QtyArrives
    102 Mon, Feb 1
    22 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • 750-MT-120, GuardDog Electronic <br>Manual Reset LWCO <br>(Water) Product Image
    Add to List
    Add to List
    750-MT-120, GuardDog Electronic Manual Reset LWCO (Water) 176207 750-MT-120, GuardDog Electronic Manual Reset LWCO (Water)
    SKU: 176207
    Brand: Mcdonnell & Miller
    (1)
    $136.20 each
    101
    Mon, Feb 1
    101
    QtyArrives
    101 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • OS-100 Outdoor Sensor Kit for HydroStat 3200-PLUS and 3250-PLUS Product Image
    Add to List
    Add to List
    OS-100 Outdoor Sensor Kit for HydroStat 3200-PLUS and 3250-PLUS 48-140 OS-100 Outdoor Sensor Kit for HydroStat 3200-PLUS and 3250-PLUS
    SKU: 48-140
    Brand: Hydrolevel
    (5)
    $38.80 each
    18
    Mon, Feb 1
    18
    QtyArrives
    18 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 150S-M-HD, Head for Float Combo LWCO Pump Ctrl <br>w/ Man. Reset (Steam) Product Image
    Add to List
    Add to List
    150S-M-HD, Head for Float Combo LWCO Pump Ctrl w/ Man. Reset (Steam) 172809 150S-M-HD, Head for Float Combo LWCO Pump Ctrl w/ Man. Reset (Steam)
    SKU: 172809
    Brand: Mcdonnell & Miller
    (1)
    $579.87 each
    54
    Mon, Feb 1
    54
    QtyArrives
    54 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • Safgard 400 Non-Cycling Steam Primary LWCO  - 24V Product Image
    Add to List
    Add to List
    Safgard 400 Non-Cycling Steam Primary LWCO - 24V 45-400-HYDROLEVEL Safgard 400 Non-Cycling Steam Primary LWCO - 24V
    SKU: 45-400-HYDROLEVEL
    Brand: Hydrolevel
    (13)
    $176.78 each
    140
    Mon, Feb 1
    170
    QtyArrives
    140 Mon, Feb 1
    30 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • PA-800, Probe Assembly for 750, 750-MT-120 & PS800 Series Product Image
    Add to List
    Add to List
    PA-800, Probe Assembly for 750, 750-MT-120 & PS800 Series 354081 PA-800, Probe Assembly for 750, 750-MT-120 & PS800 Series
    SKU: 354081
    Brand: Mcdonnell & Miller
    (1)
    $56.90 each
    38
    Mon, Feb 1
    38
    QtyArrives
    38 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • CTRD-101, Cartridge & Strainer Kit, Model<br>CTRD-101 Product Image
    Add to List
    Add to List
    CTRD-101, Cartridge & Strainer Kit, Model CTRD-101 310453 CTRD-101, Cartridge & Strainer Kit, Model CTRD-101
    SKU: 310453
    Brand: Mcdonnell & Miller
    (11)
    $122.99 each
    25
    Mon, Feb 1
    25
    QtyArrives
    25 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • 67-12, Sylphon Gasket <br>for 67 & 80 Product Image
    Add to List
    Add to List
    67-12, Sylphon Gasket for 67 & 80 318900 67-12, Sylphon Gasket for 67 & 80
    SKU: 318900
    Brand: Mcdonnell & Miller
    (1)
    $4.74 each
    74
    Mon, Feb 1
    74
    QtyArrives
    74 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
  • Safgard 170SV LWCO w/ Auto Reset, Shorter Probe - 120V Product Image
    Add to List
    Add to List
    Safgard 170SV LWCO w/ Auto Reset, Shorter Probe - 120V 45-175 Safgard 170SV LWCO w/ Auto Reset, Shorter Probe - 120V
    SKU: 45-175
    Brand: Hydrolevel
    (4)
    $85.70 each
    87
    Mon, Feb 1
    101
    QtyArrives
    87 Mon, Feb 1
    14 Wed, Feb 3 – Thu, Feb 4
    Questions? Call 1-888-757-4774
    Add to List
  • Model 3150 HydroStat for Oil Boilers (Temperature Limit & LWCO) Product Image
    Add to List
    Add to List
    Model 3150 HydroStat for Oil Boilers (Temperature Limit & LWCO) 48-3150 Model 3150 HydroStat for Oil Boilers (Temperature Limit & LWCO)
    SKU: 48-3150
    Brand: Hydrolevel
    (5)
    $142.59 each
    20
    Mon, Feb 1
    20
    QtyArrives
    20 Mon, Feb 1
    Questions? Call 1-888-757-4774
    Add to List
FAQs, Manuals & Videos

Resources

Articles

  • A low water cutoff is a device that detects when the fluid level in hot water and steam boilers drops below the minimum safe operating level specified by the boiler manufacturer. If this should occur, the low water cutoff will cut-off the burner and shut down the boiler. If a boiler is "dry-fired" (burned without water in it), it can result in boiler failure, or a possible fire/explosion. The low water cutoff can therefore be one of the most important safety devices in your hydronic heating system. Low water cutoffs are available in line voltage or low voltage models, for either water or steam systems.

    We carry a wide selection of Taco, McDonnell and Miller, and Hydrolevel low water cutoffs for residential, commercial, and industrial boiler applications.

NEED HELP?

888-757-4774
Closed Now: Phone Hours
Monday – Thursday
8am–7:45pm ET
Friday
9am–7:45pm ET
  • Product Image

  • Product Image

    Select 2 to 3 items to compare

  • Product Image

    Compare up to 1 more item

Why don't we show the price of this item?

We try to always offer you the lowest prices possible, but some manufacturers require that we only show these low prices once you take further action.

To see the price, simply add the item to your cart or sign in.