Skip to content
Free Local Pickup ● Ship to Your Hometown Store
Pro & Contractor Accounts ● Apply for Net Terms
100,000+ Products ● Trusted American Hardware Brands
FAQ Shipping & Returns Order Lookup Contact Account
Southwire 250 ft. 18/4 Solid Copper Thermostat Wire

Southwire 250 ft. 18/4 Solid Copper Thermostat Wire

Made in America

Support American manufacturers + independent hardware retailers in one purchase.

Enhance your HVAC setup with the Southwire 250 ft. 18/4 Solid Copper Thermostat Wire, offering durability and superior conductivity for reliable performance.
Southwire MPN 553040407
Sold Locally Only

This product isn’t sold on our website — see your local hardware store.

Typical Store Price i
Typical store price: low $0.99, average $0.59
In-Store Exclusive

This one's worth the trip to the store.

Brands like Weber, Milwaukee, Yeti, and DeWalt restrict where their products can be sold online — and for good reason. In-store buyers get authentic products, full manufacturer warranty, and access to pricing that simply isn't allowed to be advertised on the web.

  • Authorized dealer network · Full manufacturer warranty & support
  • Guaranteed authentic · No counterfeits, no gray-market resellers
  • The brands set these standards · Be wary of sellers who don't follow them
Why isn't this online? The whole story →
Shop Local · Support Independent

Every order helps keep your local hardware store on the corner.

Why we built NHG
You might find it for less locally. Independent retailers often offer competitive pricing — some products are even cheaper in-store than online.
Real expert advice — not search results. Independent hardware staff know their inventory and the local conditions you're working in.
Keep the neighborhood working. Every dollar spent at an independent retailer returns roughly 3x more to your local economy than at a national chain.

About Product Overview

Upgrade your wiring solutions with the Southwire 250 ft. 18/4 Solid Copper Thermostat Wire, the perfect choice for any HVAC system installation or thermostat application. Crafted with precision and reliability in mind, this thermostat wire is essential for ensuring optimal performance in your heating and cooling systems.

With its 18-gauge solid copper construction, this wire delivers exceptional conductivity and durability. It's designed to handle a variety of applications, making it an ideal choice for both residential and commercial use.

  • Length: 250 ft. for extended reach, allowing you to cover large areas with ease.
  • Conductor Material: High-quality copper ensures superior conductivity and performance.
  • Flame Retardant: Safety is a priority with this wire, as it features flame-retardant properties.
  • Insulation Material: Made with PVC, providing excellent insulation and protection against wear and tear.
  • Ground Material: Solid copper grounding for added safety and reliability.

The Southwire 250 ft. 18/4 Solid Copper Thermostat Wire is not only versatile but also user-friendly, making installation a breeze. Whether you're upgrading your thermostat or setting up a new system, this wire is your go-to solution.

Don’t compromise on quality when it comes to your electrical installations. Choose the Southwire 250 ft. 18/4 Solid Copper Thermostat Wire and experience peace of mind with every connection! Order yours today!

The Details Specifications

Brand Southwire
SKU 33299
UPC 029892354084
Unit 0
Case Pack Quantity 4 per case
Retail Unit Quantity 250
Unit of Measure 250 SO
Dimensions (L × W × H) 4 × 7 × 7
Weight 7 lbs
Cubic Feet 0.1338 ft³
Country of Origin USA
Safety Data Sheet (SDS) Manufacturer documentation · opens in new tab

Ask our counter. Or theirs.

Most hardware stores can do more than you think. If we can't help you, the folks down the street probably can — just ask at the counter.

What we offer
Free Local Pickup Ship to your hometown store
Pro & Gov Accounts Net terms · tax-exempt
Ships Nationwide From our distribution network
Independent Network Real hardware stores
$0.68 of every dollar spent at a local independent business stays in the community. At a national chain, it's about fifteen cents. Civic Economics, multi-city retail studies
Their Counter
Try local first · we'll wait

The stores we send you to are local and independently run — often for generations, the kind of place where someone behind the counter knows the regulars. We don't own them. We just think they deserve the foot traffic. They can put most of what we sell on their next truck. Ask there before you check out here.

Find a local store →
Mon–Fri 6–5 PST
Independent hardware retailer? Join the network →
About our directory. National Hardware Group is an independent retailer and directory. The local stores we list and link to are separately owned and operated — we have no ownership stake in any of them, and most pay us nothing to be included. That includes plenty of stores flying a co-op banner that people don't realize are locally owned and run, not operated by a corporation. Store owners can choose to upgrade their listing for an enhanced presence or pickup features, but the base directory is free, and inclusion is never a paid endorsement.

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare

Compare