1-Zone Switching Relay


Brand: Taco

Mfr Part#: SR501-4

UPC#: 687752390384

Availability: In Stock
Usually ships: within 1 business day
Qty Price
$52.95 / each
  • Description
  • Literature
  • Reviews (6)
  • FAQs (1)

Taco SR501 Single zone switching relay is a standard equipment for every installer. It can easily replace any brand made by any manufacturer, and will even fit into the existing metal enclosure without rewiring incoming connections. The SR501 single zone switching relay is UL and CSA listed, uses a standard “ice cube” replaceable relay and is compatible with conventional and programmable thermostats. External indicator lights provide instant diagnostic feedback, making a snap of service calls or new installation start-ups.


  • External Indicator Lights;
  • Switchable Priority;
  • Simplified Wiring;
  • Fully Enclosed Snap-Out Relays;
  • Compact Design;
  • Fuse Protected;
  • 100% Factory Tested;
  • Isolated End Switch;
  • Contractor Friendly PC Board Layout;
  • Universal Thermostat Compatibility;
  • UL and CSA Approved;
  • 24 Volt Power Input or Output Terminal;
  • Extended 3 Year Warranty;
  • Made in the USA.

Technical Specifications:

  • Zones: 1;
  • Power: 120VAC;
  • Max combined load: 5.0 AMPs;
  • Dimensions: 4.25" wide x 5.25" high x 2.75" deep.
1-Zone Switching Relay has an average 5.0 out of 5 rating based on 6 user reviews.
Taco relay is great!
By Mitch,plumber (from Los Angeles, CA) on 10/5/2016
Great product!
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good quality works great
By Verified Buyer on 1/24/2016
Good relay easy to hook up with several wiring options good company to work with. Fast shipping.
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excellent company to deal with, very fast shipping.
By Dan (from 14843) on 11/26/2015
excellent company to deal with, very fast shipping.
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Quality product
By Verified Buyer on 5/14/2015
A little pricey, but a good unit.
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i got it delivered very fast
By john v. (from vestal ny) on 2/15/2012
it was very easy to install it, no problem at all.working good
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Works well and looks good
By Peter (from New Jersey) on 2/1/2012
I bought the switching relay to replace the old 20 year old relay, since it did not seem to work anymore. Installing the Taco SR501 was a breeze. I ran new wire (T-Stat, to Boiler, and new power supply) and installed everything in about an hour. Works like it's supposed to!
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I have a sr504 relay control. I need to add 1 more zone. Can I use a sr501 and add it to the sr504? Thanks for your answer.
Read 1 answer
Only -EXP Taco switching relay models are expandable. Regular models, including this one cannot be expanded. Also note that in order to expand an existing -EXP control, your second controls also has to be the -EXP model.
Answered on 12/10/2013 by PexUniverse Customer Service
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