120V and 24V SPST relays provide reliable switching in HVAC systems. Replacing faulty relays ensures safe operation, prevents electrical issues, and maintains efficient, dependable heating and cooling performance.

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-13%Resideo R841D1036 Electric Heater Relay W/SPST Switching 24VSpecial Price $81.60 Regular Price $93.84
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-10%Resideo L8124G1020 SPST Triple Aquastat Relay Vertical MountSpecial Price $403.45 Regular Price $447.83- -10%Resideo R841E1068 SPST Electric Heater Relay 240VSpecial Price $264.21 Regular Price $293.27Out of stock
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- -13%Functional Devices RIBXLSRA SPST Adjustable Current Sensor & Relay 1.25-1.5ASpecial Price $131.94 Regular Price $151.73
- -13%Schneider Electric (Square D) 8501CO6V20 SPST Relay 1-N/O 30A 120VSpecial Price $55.82 Regular Price $64.19Out of stock
HVAC SPST Relay Replacement Components for Electrical Systems
HVAC SPST relay replacement parts support safe, reliable operation in heating, ventilation, and air conditioning systems. Acting as electrical switches, they control circuits for fans, compressors, and other components. A 120V SPST relay enables dependable switching in higher-voltage circuits while helping protect equipment from overloads.
Similarly, a 24V SPST relay is used in low-voltage HVAC applications, helping regulate the operation of thermostats, motors, and other control devices. Proper maintenance and timely replacement of SPST relays prevent issues such as intermittent operation, buzzing noises, short cycling, or complete system shutdown.
These relays ensure consistent performance, enhance system efficiency, and extend the lifespan of connected equipment. Regular inspection and replacement of worn SPST relays help maintain smooth and safe HVAC operation, delivering consistent comfort across residential and commercial applications.
At PartsHnC, we offer SPST normally open relays, SPST enclosed relays, SPST panel relays, and SPST low voltage relays 20A. Compatible with trusted brands like Functional Devices, Sterling, General Electric, Miscellaneous Product, and Resideo for reliable HVAC performance.
FAQs
How do I know if an SPST relay needs replacement?
Common signs include buzzing or clicking noises, intermittent operation, motors not starting, or complete system shutdown.
How long does an SPST relay typically last?
SPST relays usually last several years, depending on system usage, electrical load, and maintenance.
What causes an SPST relay to fail?
Common causes include wear and tear, electrical surges, overheating, or corrosion, which can lead to intermittent operation or system shutdowns.
What is the difference between SPST and SPDT relays?
SPST controls one circuit with a single switch; SPDT can switch between two circuits using one input.
Can a faulty SPST relay damage HVAC equipment?
Yes, it can cause motors or compressors to overheat, short cycle, or fail, risking further system damage.
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