Pros, Join Our TradeMaster Program!
  • 1 Zone Switching Relay Product Image
    Add to List
    Add to List
    1 Zone Switching Relay SR501-4 1 Zone Switching Relay
    SKU: SR501-4
    Brand: Taco
    (122)
    $60.00 each
    836
    Thu, Aug 20
    2,477
    QtyArrives
    836 Thu, Aug 20
    1,641 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 2 Zone Switching Relay Product Image
    Add to List
    Add to List
    2 Zone Switching Relay SR502-4 2 Zone Switching Relay
    SKU: SR502-4
    Brand: Taco
    (20)
    $142.00 each
    558
    Thu, Aug 20
    1,538
    QtyArrives
    558 Thu, Aug 20
    980 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 3 Zone Switching Relay Product Image
    Add to List
    Add to List
    3 Zone Switching Relay SR503-4 3 Zone Switching Relay
    SKU: SR503-4
    Brand: Taco
    (38)
    $150.00 each
    566
    Thu, Aug 20
    1,122
    QtyArrives
    566 Thu, Aug 20
    556 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 4 Zone Switching Relay Product Image
    Add to List
    Add to List
    4 Zone Switching Relay SR504-4 4 Zone Switching Relay
    SKU: SR504-4
    Brand: Taco
    (122)
    $182.00 each
    385
    Thu, Aug 20
    896
    QtyArrives
    385 Thu, Aug 20
    511 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 6 Zone Switching Relay Product Image
    Add to List
    Add to List
    6 Zone Switching Relay SR506-4 6 Zone Switching Relay
    SKU: SR506-4
    Brand: Taco
    (122)
    $240.00 each
    243
    Thu, Aug 20
    466
    QtyArrives
    243 Thu, Aug 20
    223 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 2 Zone 120V Switching Relay with DPST switching Product Image
    Add to List
    Add to List
    2 Zone 120V Switching Relay with DPST switching RA832A1066 2 Zone 120V Switching Relay with DPST switching
    SKU: RA832A1066
    Brand: Honeywell
    (28)
    $75.89 each
    264
    Thu, Aug 20
    264
    QtyArrives
    264 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 6 Zone Switching Relay<br>w/ Priority Product Image
    Add to List
    Add to List
    6 Zone Switching Relay w/ Priority SR506-EXP-4 6 Zone Switching Relay w/ Priority
    SKU: SR506-EXP-4
    Brand: Taco
    (13)
    $248.00 each
    157
    Thu, Aug 20
    273
    QtyArrives
    157 Thu, Aug 20
    116 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 4 Zone Switching Relay<br>w/ Priority Product Image
    Add to List
    Add to List
    4 Zone Switching Relay w/ Priority SR504-EXP-4 4 Zone Switching Relay w/ Priority
    SKU: SR504-EXP-4
    Brand: Taco
    (27)
    $190.00 each
    98
    Thu, Aug 20
    139
    QtyArrives
    98 Thu, Aug 20
    41 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 3 Zone Switching Relay<br>w/ Priority Product Image
    Add to List
    Add to List
    3 Zone Switching Relay w/ Priority SR503-EXP-4 3 Zone Switching Relay w/ Priority
    SKU: SR503-EXP-4
    Brand: Taco
    (27)
    $158.00 each
    54
    Thu, Aug 20
    164
    QtyArrives
    54 Thu, Aug 20
    110 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 1 Zone 120V Switching Relay w/ Internal Transformer, 1 SPST Product Image
    Add to List
    Add to List
    1 Zone 120V Switching Relay w/ Internal Transformer, 1 SPST RA89A1074 1 Zone 120V Switching Relay w/ Internal Transformer, 1 SPST
    SKU: RA89A1074
    Brand: Honeywell
    (15)
    $60.99 each
    158
    Thu, Aug 20
    158
    QtyArrives
    158 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • Switching Relay w/ Internal Transformer DPST Line Voltage Relays Product Image
    Add to List
    Add to List
    Switching Relay w/ Internal Transformer DPST Line Voltage Relays R845A1030 Switching Relay w/ Internal Transformer DPST Line Voltage Relays
    SKU: R845A1030
    Brand: Honeywell
    (9)
    $77.99 each
    163
    Thu, Aug 20
    163
    QtyArrives
    163 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • Replacement Fuse - <br>5 Amp (10 Pack) Product Image
    Add to List
    Add to List
    Replacement Fuse - 5 Amp (10 Pack) SR5A-005RP Replacement Fuse - 5 Amp (10 Pack)
    SKU: SR5A-005RP
    Brand: Taco
    (2)
    $13.99 each
    42
    Thu, Aug 20
    127
    QtyArrives
    42 Thu, Aug 20
    85 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • Replacement Fuse - <br>6 Amp (10 Pack) Product Image
    Add to List
    Add to List
    Replacement Fuse - 6 Amp (10 Pack) SR6A-001RP Replacement Fuse - 6 Amp (10 Pack)
    SKU: SR6A-001RP
    Brand: Taco
    (5)
    $16.99 each
    64
    Thu, Aug 20
    152
    QtyArrives
    64 Thu, Aug 20
    88 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • Universal Switching Relay w/ Internal Transformer Product Image
    Add to List
    Add to List
    Universal Switching Relay w/ Internal Transformer R8845U1003 Universal Switching Relay w/ Internal Transformer
    SKU: R8845U1003
    Brand: Honeywell
    (17)
    $58.99 each
    183
    Thu, Aug 20
    183
    QtyArrives
    183 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 2 Zone Pump Controller Switching Relay with Priority Protection Product Image
    Add to List
    Add to List
    2 Zone Pump Controller Switching Relay with Priority Protection SP-82 2 Zone Pump Controller Switching Relay with Priority Protection
    SKU: SP-82
    Brand: Azel Technologies
    (8)
    $103.95 each
    57
    Thu, Aug 20
    57
    QtyArrives
    57 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 6 Zone Expandable Switching Relay Product Image
    Add to List
    Add to List
    6 Zone Expandable Switching Relay ARM6P 6 Zone Expandable Switching Relay
    SKU: ARM6P
    Brand: Argo
    (28)
    $234.99 each
    248
    Thu, Aug 20
    248
    QtyArrives
    248 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 1 Zone Switching Relay Product Image
    Add to List
    Add to List
    1 Zone Switching Relay AR822II 1 Zone Switching Relay
    SKU: AR822II
    Brand: Argo
    (5)
    $56.99 each
    206
    Thu, Aug 20
    206
    QtyArrives
    206 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 4 Zone Expandable Switching Relay Product Image
    Add to List
    Add to List
    4 Zone Expandable Switching Relay ARM4P 4 Zone Expandable Switching Relay
    SKU: ARM4P
    Brand: Argo
    (28)
    $205.99 each
    207
    Thu, Aug 20
    207
    QtyArrives
    207 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • Isolation Relay<br>(Up to 3 Zones) Product Image
    Add to List
    Add to List
    Isolation Relay (Up to 3 Zones) IR882 Isolation Relay (Up to 3 Zones)
    SKU: IR882
    Brand: Argo
    (14)
    $67.99 each
    44
    Thu, Aug 20
    44
    QtyArrives
    44 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 3 Zone Pump Controller Switching Relay with Priority Protection Product Image
    Add to List
    Add to List
    3 Zone Pump Controller Switching Relay with Priority Protection SP-83 3 Zone Pump Controller Switching Relay with Priority Protection
    SKU: SP-83
    Brand: Azel Technologies
    (6)
    $125.95 each
    37
    Thu, Aug 20
    37
    QtyArrives
    37 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 1 Zone Pump Controller Switching Relay w/ Surge & Fuse Protection (DPDT) Product Image
    Add to List
    Add to List
    1 Zone Pump Controller Switching Relay w/ Surge & Fuse Protection (DPDT) SP-81 1 Zone Pump Controller Switching Relay w/ Surge & Fuse Protection (DPDT)
    SKU: SP-81
    Brand: Azel Technologies
    (5)
    $53.75 each
    12
    Thu, Aug 20
    12
    QtyArrives
    12 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • 24v Replacement Relay Product Image
    Add to List
    Add to List
    24v Replacement Relay SR024-001RP 24v Replacement Relay
    SKU: SR024-001RP
    Brand: Taco
    (6)
    $24.99 each
    51
    Thu, Aug 20
    129
    QtyArrives
    51 Thu, Aug 20
    78 Mon, Aug 24 – Tue, Aug 25
    Questions? Call 1-888-757-4774
    Add to List
  • 3 Zone Expandable Switching Relay Product Image
    Add to List
    Add to List
    3 Zone Expandable Switching Relay ARM3P 3 Zone Expandable Switching Relay
    SKU: ARM3P
    Brand: Argo
    (28)
    $167.99 each
    195
    Thu, Aug 20
    195
    QtyArrives
    195 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
  • UPZCP-1 Single Zone Pump Control  Product Image
    Add to List
    Add to List
    UPZCP-1 Single Zone Pump Control 98996400 UPZCP-1 Single Zone Pump Control
    SKU: 98996400
    Brand: Grundfos
    (1)
    $59.99 each
    34
    Thu, Aug 20
    34
    QtyArrives
    34 Thu, Aug 20
    Questions? Call 1-888-757-4774
    Add to List
FAQs, Manuals & Videos

Resources

Videos

Articles

  • Switching relays are used to control the flow of water in a heating system by monitoring temperatures and adjusting boiler water temperature to match the demand. They are used in coordination with circulator pumps and programmable thermostats to control zoning in a hydronic heating system. This makes them ideal for indirect water heaters and priority zoning applications. They maximize efficiency and reduce fuel usage, which saves money. In addition, they provide intermediate switching of a line voltage device from a low voltage controller. Switching relays are available in one to six zone models, and if additional zones are required expandable models provide the ability to expand up to 20 zones.

    We offer a wide selection of Taco, Honeywell , Argo, and Bell & Gossett switching relays for residential and light commercial applications.

NEED HELP?

888-757-4774
Closed Now: Phone Hours
Monday – Thursday
8am–7:45pm ET
Friday
8:30am–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.