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
    47
    Wed, Jun 10
    407
    QtyArrives
    47 Wed, Jun 10
    360 Mon, Jun 15 – Tue, Jun 16
    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
    784
    Mon, Jun 15 – Tue, Jun 16
    784
    QtyArrives
    784 Mon, Jun 15 – Tue, Jun 16
    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
    44
    Wed, Jun 10
    832
    QtyArrives
    44 Wed, Jun 10
    788 Mon, Jun 15 – Tue, Jun 16
    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
    43
    Wed, Jun 10
    795
    QtyArrives
    43 Wed, Jun 10
    752 Mon, Jun 15 – Tue, Jun 16
    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
    24
    Wed, Jun 10
    137
    QtyArrives
    24 Wed, Jun 10
    113 Mon, Jun 15 – Tue, Jun 16
    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
    40
    Wed, Jun 10
    223
    QtyArrives
    40 Wed, Jun 10
    183 Thu, Jun 11
    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
    10
    Wed, Jun 10
    10
    QtyArrives
    10 Wed, Jun 10
    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
    8
    Wed, Jun 10
    9
    QtyArrives
    8 Wed, Jun 10
    1 Thu, Jun 11
    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
    30
    Wed, Jun 10
    41
    QtyArrives
    30 Wed, Jun 10
    11 Mon, Jun 15 – Tue, Jun 16
    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
    (13)
    $60.99 each
    39
    Wed, Jun 10
    112
    QtyArrives
    39 Wed, Jun 10
    73 Thu, Jun 11
    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
    17
    Wed, Jun 10
    121
    QtyArrives
    17 Wed, Jun 10
    104 Thu, Jun 11
    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
    41
    Wed, Jun 10
    126
    QtyArrives
    41 Wed, Jun 10
    85 Mon, Jun 15 – Tue, Jun 16
    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
    123
    Wed, Jun 10
    215
    QtyArrives
    123 Wed, Jun 10
    92 Thu, Jun 11
    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
    36
    Wed, Jun 10
    124
    QtyArrives
    36 Wed, Jun 10
    88 Mon, Jun 15 – Tue, Jun 16
    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
    12
    Wed, Jun 10
    12
    QtyArrives
    12 Wed, Jun 10
    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
    (27)
    $234.99 each
    21
    Wed, Jun 10
    171
    QtyArrives
    21 Wed, Jun 10
    150 Thu, Jun 11
    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
    26
    Wed, Jun 10
    176
    QtyArrives
    26 Wed, Jun 10
    150 Thu, Jun 11
    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
    (27)
    $205.99 each
    11
    Wed, Jun 10
    161
    QtyArrives
    11 Wed, Jun 10
    150 Thu, Jun 11
    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
    16
    Wed, Jun 10
    23
    QtyArrives
    16 Wed, Jun 10
    7 Thu, Jun 11
    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
    9
    Wed, Jun 10
    9
    QtyArrives
    9 Wed, Jun 10
    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
    5
    Wed, Jun 10
    5
    QtyArrives
    5 Wed, Jun 10
    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
    (27)
    $167.99 each
    17
    Wed, Jun 10
    167
    QtyArrives
    17 Wed, Jun 10
    150 Thu, Jun 11
    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
    19
    Wed, Jun 10
    103
    QtyArrives
    19 Wed, Jun 10
    6 Thu, Jun 11
    78 Mon, Jun 15 – Tue, Jun 16
    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
    $59.99 each
    39
    Wed, Jun 10
    39
    QtyArrives
    39 Wed, Jun 10
    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.