DESCRIPTION
Carrier HK25SZ359A / Defrost Control Circuit Board 990-197 – HVAC & Refrigeration: Controls & Circuit Boards
The Carrier HK25SZ359A / Defrost Control Circuit Board 990-197 is an advanced component designed for efficient HVAC system management. It regulates defrost cycles to optimize performance and increase the longevity of your system.
- Voltage Rating: 24V AC
- Operating Temperature Range: -40°F to 158°F
- Dimensions: 4.75 x 2.75 x 1.25 inches
- Compatibility: Fits a variety of Carrier HVAC units
- Board Function: Electronic defrost control for precise operation
Compared to industry standards, the Carrier HK25SZ359A / Defrost Control Circuit Board 990-197 offers enhanced reliability and improved functionality. While many standard boards may not support precise temperature ranges or broad compatibility, this model delivers accurate timing and seamless integration with multiple Carrier units. It stands out for its robust engineering and proven durability, making it a preferred option for both replacements and new installs.
Key Technical Advantages:
- Advanced defrost control logic reduces ice build-up and prolongs system life
- Wide operating temperature range ensures performance in extreme conditions
- Simple plug-and-play installation saves time and reduces service costs
- Durable components minimize maintenance and failure rates
- Fully tested and backed by Carrier’s industry-leading reputation for quality
Technology and Performance
The Carrier HK25SZ359A / Defrost Control Circuit Board 990-197 provides superior control over your HVAC unit’s defrost operations. Its intelligent programming ensures that your system only enters defrost mode when needed, maximizing both energy efficiency and comfort. Thanks to its state-of-the-art electronic circuitry, this HVAC control board achieves fast, accurate responses to environmental changes.
Designed for professional-grade performance, this control board meets rigorous HVAC & Refrigeration standards. Whether you’re completing routine maintenance or handling a critical repair, the Carrier HK25SZ359A provides dependable, high-performance operation you can trust. With its leading-edge features, it represents the next step in reliable system management for HVAC professionals and homeowners alike.
SHIPPING
Shipping Policy
At Willards HVAC Supply, we take pride in fast, reliable shipping for both standard and freight orders. Please review our shipping terms carefully to understand how your order will be processed and delivered.
1. Order Processing Time
- All orders—both freight and non-freight—are processed and shipped within 24 hours of payment confirmation (excluding weekends and holidays).
- Orders placed after business hours will be processed the following business day.
2. Shipping Methods
We ship using a combination of standard parcel carriers (UPS, FedEx, USPS) and LTL freight carriers depending on the size, weight, and type of product ordered.
- Non-Freight Items: These items ship via standard ground or expedited carrier service. Overnight shipping is available for these items.
- Freight Items: Large or heavy products that require palletization will ship via an LTL freight carrier. Overnight shipping is not available for freight shipments.
3. Delivery Times
- Standard Ground: Most deliveries arrive within 3–5 business days after shipment.
- Overnight Shipping: When selected at checkout (for non-freight items only), we guarantee delivery within 48 hours from when the order is placed.
If we fail to deliver your overnight shipment within 48 hours of shipment, you will receive a full refund of the overnight shipping charge.
4. Overnight Shipping Rate
- Overnight shipping is available at a flat rate of $100 per order (for eligible non-freight items).
- This service includes expedited processing and guaranteed delivery within 48 hours, or your overnight charge will be refunded.
5. Freight Shipping Details
- Freight shipments are delivered curbside to commercial or residential addresses.
- The customer is responsible for unloading the item(s) from the truck unless a liftgate service is purchased or included.
- Inspect all freight deliveries before signing the carrier’s delivery receipt. Note any visible damage immediately and contact us within 24 hours.
6. Tracking Information
Once your order ships, a tracking number will be provided via email. Freight shipments may include a Bill of Lading (BOL) number for status updates through the carrier’s website.
7. Shipping Restrictions
- We currently ship within the contiguous United States only.
- We do not ship to P.O. boxes, APO/FPO addresses, or international destinations.
8. Delays Beyond Our Control
While we strive to meet all delivery timelines, Willards HVAC Supply is not responsible for carrier delays caused by weather, natural events, or other circumstances beyond our control. However, our overnight delivery guarantee still applies to qualifying orders when carrier fault is not involved.
9. Contact Us
If you have any questions about shipping or tracking your order, please contact us at support@willardshvacsupply.com.
Warranty
1-Year Limited Warranty Policy
At Willard’s HVAC Supply LLC, we provide a limited one-year warranty from the date the product is received. This warranty covers defects in materials or workmanship under normal use and installation.
What’s Covered:
- Defective parts due to material or manufacturing faults.
- Product failures under normal, proper installation and use.
Our Promise:
If a defect occurs within one year, we’ll either repair, replace, or refund the product at our discretion.
Not Covered:
- Improper installation, wiring, or misdiagnosis.
- Damage from misuse, neglect, or incompatible systems.
- Normal wear, cosmetic damage, or acts of nature (fire, flood, power surge).
- Labor or shipping costs related to removal or reinstallation.
- Items sold “as-is” or marked “final sale.”
Warranty Claim Steps:
- Email support@willardshvacsupply.com with your order number, part number, description, and photos or video of the issue.
- If approved, we’ll provide a prepaid shipping label for return.
- Drop the return off within two (2) business days of receiving the label.
After inspection, we’ll confirm if the part qualifies for repair, replacement, or refund.
Customer Responsibilities:
- Ensure diagnosis and installation were performed by a qualified technician.
- Return the item in original condition.
- If no defect is found, shipping and handling charges will apply.
Limitations:
Our liability is limited to repair, replacement, or refund. We are not responsible for labor, downtime, or indirect damages.
Non-Transferable:
This warranty applies only to the original purchaser and installation.
Governing Law:
This warranty is governed by South Carolina law.
Contact Info
Willard’s HVAC Supply, LLC
311 Belair Road
North Augusta, SC 29841
Phone: (803) 510-7290
Email: support@willardshvacsupply.com
Use our live chat to text with us.
Hours: Mon–Fri 8AM–5PM (EST)
Doing Business With US
- 1 YEAR WARRANTYFlexibe warranty on all items.
- DISCOUNTS AVAILABLEContact us for savings.
- IMMEDIATE PHONE SUPPORT(803) 510-7290
- FREE SHIPPINGFree shipping on all orders.
- OVERNIGHT AVAILABILITYGet your shipment tomorrow.
- CHAT SUPPORTYour preference for communication.
- PRICE MATCHWe will price-match most competitors.
- SMALL BUSINESSSupport a small business in the USA.
- INFORMATION PRIVACYTop industry standards for security.



