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High Limit Aquastat Relay with 15°F Fixed Differential - 5.1 W x 5 H x 7 D
Our Price:$439.94This high limit aquastat relay is an HVAC temperature-control component for professionals servicing heating systems. It provides high-limit control with a fixed differential to support...
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High Limit Aquastat Relay, 180°F to 240°F Range
Our Price:$449.94This high limit aquastat relay is a temperature control for HVAC professionals and facility maintenance teams who need to monitor and manage system temperature. It provides a practical control point...
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High or Low Limit Aquastat Controller
Our Price:$249.94This high or low limit aquastat controller is for HVAC professionals who need to manage temperature limits in compatible systems. It helps support temperature-based control by opening the circuit as...
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High-Limit Circulator Aquastat Controller
Our Price:$375.94This high-limit circulator aquastat controller is for HVAC professionals who need to manage a circulator and high-limit temperature control in an HVAC system. It provides a dedicated controller for...
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High-Limit Manual-Reset Aquastat Controller
Our Price:$299.94This high-limit manual-reset aquastat controller is for HVAC technicians and maintenance teams who need to monitor operating temperature in aquastat applications. Its high-limit control function...
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High-Limit Manual-Reset Aquastat Controller, 100 to 240°F
Our Price:$355.94This high-limit manual-reset aquastat controller is for HVAC professionals and facility maintenance teams who need to monitor operating temperature in aquastat applications. It provides a...
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High-Limit Manual-Reset Aquastat Controller, 130°F to 270°F
Our Price:$279.94This high-limit manual-reset aquastat controller is for HVAC technicians and facility maintenance teams who need to monitor temperature in applicable heating-control systems. It provides a high-limit...
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High-Limit Oil Aquastat Relay, 120V
Our Price:$339.94This high-limit oil aquastat relay is a temperature control for HVAC technicians and maintenance professionals working with oil heating equipment. It helps manage system temperature within its...
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High-Pressure SPST Pressure Switch, 300 PSI Open / 200 PSI Close
Our Price:$25.94This high-pressure SPST pressure switch is for HVAC service professionals who need to control condenser fan cycling based on system pressure. It opens on a pressure rise at 300 PSI and closes at 200...
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High-Pressure SPST Pressure Switch, 400 PSI Open / 300 PSI Close
Our Price:$28.94This high-pressure SPST pressure switch is for HVAC technicians and service professionals who need to control condenser fan cycling based on system pressure. It opens on a pressure rise at 400 PSI...
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High-Pressure SPST Pressure Switch, 600 PSI Open / 475 PSI Close
Our Price:$18.99This high-pressure SPST pressure switch is for HVAC technicians and service professionals who need to control condenser fan cycling based on system pressure. It opens on a pressure rise at 600 PSI...
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High-Pressure SPST Switch, 350 PSI Open / 250 PSI Close
Our Price:$19.74This high-pressure SPST switch is for HVAC professionals who need to cycle condenser fans in response to system pressure. It opens on a pressure rise at 350 PSI and closes at 250 PSI to support...
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High-Pressure SPST Switch, 400 PSI Open / 200 PSI Close
Our Price:$21.49This high-pressure SPST switch is for HVAC technicians and service professionals who need to cycle condenser fans in response to system pressure. It opens on a pressure rise at 400 PSI and closes at...
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High-Pressure SPST Switch, 400 PSI Open / 280 PSI Close
Our Price:$30.94This high-pressure SPST switch is for HVAC technicians and service professionals who need to monitor pressure and cycle condenser fans. It opens on a pressure rise at 400 PSI and closes at 280 PSI...
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High-Pressure SPST Switch, 425 PSI Open / 325 PSI Close
Our Price:$31.94This high-pressure SPST switch is for HVAC technicians and service professionals who need to cycle a condenser fan based on system pressure. It opens on a pressure rise at 425 PSI and closes at 325...
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High-Pressure SPST Switch, 450 PSI Open / 250 PSI Close
Our Price:$17.99This high-pressure SPST pressure switch is for HVAC service professionals and technicians working with condenser fan cycling controls. It opens on a pressure rise at 450 PSI and closes at 250 PSI to...
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High-Pressure SPST Switch, 610 PSI Open / 420 PSI Close
Our Price:$31.94This high-pressure SPST switch is for HVAC professionals and service teams who need to control condenser fan cycling based on system pressure. It opens on a pressure rise at 610 PSI and closes at 420...
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High/Low Limit Aquastat Controller
Our Price:$279.94This high/low limit aquastat controller is for HVAC professionals and facility maintenance teams who need to manage temperature limits in HVAC control applications. It provides adjustable temperature...
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High/Low Limit Aquastat Controller, 100°F to 240°F
Our Price:$259.94This aquastat controller is for HVAC technicians and facility maintenance teams that need to manage high- or low-limit temperature control. It provides a practical temperature-control component for...
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High/Low Limit Aquastat Controller, 130°F to 270°F
Our Price:$405.94This high/low limit aquastat controller is for HVAC professionals and maintenance teams who need to monitor and control temperature limits in compatible equipment. It supports temperature-based...
HVAC Controls, Parts & Service: Everything You Need to Keep Your System Running
Whether you're replacing a worn component, upgrading system controls, or performing routine maintenance, this category covers the essential parts and equipment that keep heating and cooling systems operating efficiently. Use the subcategory paths below to find exactly what your job requires.
Choose your starting point
Popular examples in this category
Keeping HVAC Systems Operational and Efficient
These products support repair, maintenance, and replacement tasks across residential and commercial HVAC systems. From failed capacitors to worn pump bearings, having the right part on hand reduces downtime, restores comfort, and extends the working life of heating and cooling equipment.
Start With the System and the Problem
Identify the system type (hydronic, forced air, refrigeration), the failing or worn component, and the specifications required—voltage, flow rate, pressure rating, or physical dimensions. Matching specs precisely prevents compatibility issues and callbacks on completed jobs.
Where These Parts and Controls Are Used
Common applications include boiler and hydronic heating systems, split and packaged air conditioning units, commercial refrigeration, and ventilation systems. Parts like circulator pumps, capacitors, and aquastats are used in both new installations and service replacement scenarios.
Sourcing Tips and Service Considerations
Always verify OEM specifications or cross-reference part numbers before ordering. For service work, stocking common failure items—capacitors, condensate pumps, and bearings—reduces truck rolls and speeds up repairs. Cleaning equipment supports preventive maintenance programs that lower long-term service costs.
Which Subcategory Do You Need? A Quick Reference
Match your service need to the right subcategory path using this guide.
| Need | Best Fit Subcategory | Why It Matters |
|---|---|---|
| Control boiler water temperature | Aquastats | Aquastats regulate when the boiler fires based on water temperature setpoints, protecting the system and maintaining efficiency |
| Replace a failed motor or pump component | Bearings or Circulator Pump Accessories | Bearings and accessories allow targeted repair without full pump replacement, saving cost and labor time |
| Restore circulation in a hydronic system | Circulator Pumps | The right pump must match system flow rate and head pressure to maintain proper heat distribution |
| Fix a non-starting AC or refrigeration unit | Capacitors or Compressors | Capacitors are a common low-cost fix; if the compressor itself has failed, replacement is required |
| Remove standing water from drain pans | Condensate Pumps | Condensate pumps prevent water damage and mold by actively removing condensate when gravity drainage isn't available |
| Perform seasonal system cleaning | HVAC Cleaning Equipment | Regular coil and drain cleaning maintains airflow, efficiency, and indoor air quality across all system types |
Plan the right fit before choosing
Step 1: Identify the System and Failure Point
Before selecting any part or control, confirm the system type and the specific component that needs attention. Hydronic systems rely heavily on circulator pumps, aquastats, and bearings, while refrigerant-based systems commonly require capacitors and compressors.
- Note the system voltage, BTU capacity, and fluid or refrigerant type
- Check whether the failure is electrical, mechanical, or related to flow and pressure
- Confirm whether you need an exact replacement or an equivalent cross-reference
Step 2: Match Specifications to the Application
Each subcategory has critical spec requirements. Capacitors must match microfarad and voltage ratings. Circulator pumps require correct flow rate and head pressure. Aquastats need the right temperature range for the system they control.
- Use the existing part number or equipment nameplate data as your starting point
- For pumps and compressors, verify flange size, port configuration, and mounting style
- For controls like aquastats, confirm setpoint range and differential settings
Step 3: Plan for Preventive Maintenance
Many service calls can be reduced by stocking high-failure-rate components and scheduling regular cleaning and inspection. HVAC cleaning equipment and condensate pump maintenance are often overlooked until a system failure occurs.
- Stock capacitors and condensate pumps as common wear items for service vans
- Schedule coil and drain line cleaning seasonally to prevent efficiency loss
- Inspect bearings and pump accessories annually in hydronic systems
From aquastats to compressors, each subcategory focuses on a specific part or function so you can navigate directly to what you need.
Most HVAC service calls involve either an electrical component failure (capacitor, control) or a mechanical one (bearing, pump, compressor), and this category covers both.
Parts and controls in this category are used across light residential systems, large commercial HVAC installations, and industrial climate control applications.
Whether you're responding to a breakdown or running a scheduled maintenance program, this category includes parts and equipment for both approaches.
Common questions before buying
How do I know if I need a capacitor or a compressor replacement?
Start with the capacitor—it's a common, low-cost failure point that can prevent a compressor from starting. Test the capacitor first. If it checks out and the compressor still won't run, further diagnosis of the compressor is warranted.
What specifications do I need to replace a circulator pump?
You'll need the flow rate (GPM), head pressure (feet of head), pipe connection size, and voltage. Check the nameplate on the existing pump or the system design documents to confirm these values before ordering.
Can I use HVAC cleaning equipment on both residential and commercial systems?
Yes, but verify that the equipment capacity and chemical compatibility match the system size and coil material. Some commercial systems require higher-pressure coil cleaning tools than those used in residential applications.
What is an aquastat and when does it need to be replaced?
An aquastat is a temperature control device used in hydronic heating systems to regulate boiler operation. It may need replacement if the system short-cycles, fails to reach setpoint, or if the control shows signs of electrical failure during testing.
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