--- product_id: 4147562 title: "Reliance 9000509-045 Single Element Electric Thermostat" brand: "a. o. smith" price: "HK$315" currency: HKD in_stock: true reviews_count: 8 category: "A. O. Smith" url: https://www.desertcart.hk/products/4147562-reliance-9000509-045-single-element-electric-thermostat store_origin: HK region: Hong Kong --- # 240V power for rapid heating Touch control for seamless operation Digital temperature display for precision Reliance 9000509-045 Single Element Electric Thermostat **Brand:** a. o. smith **Price:** HK$315 **Availability:** ✅ In Stock ## Summary > 🌡️ Upgrade your heat game with precision and ease! ## Quick Answers - **What is this?** Reliance 9000509-045 Single Element Electric Thermostat by a. o. smith - **How much does it cost?** HK$315 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hk](https://www.desertcart.hk/products/4147562-reliance-9000509-045-single-element-electric-thermostat) ## Best For - a. o. smith enthusiasts ## Why This Product - Trusted a. o. smith brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Reliable 240V Power:** Optimized for single element electric water heaters to deliver consistent performance. - • **Effortless Installation:** Get your water heater back in action in under 20 minutes—no hassle, no fuss. - • **Sleek Wall-Mount Design:** Compact rectangular form fits discreetly, blending into any utility space. - • **Trusted Brand Assurance:** A.O. Smith quality with a solid warranty—because your comfort deserves the best. - • **Precision Temperature Control:** Digital touch interface lets you dial in the perfect heat every time. ## Overview The Reliance 9000509-045 is a single element electric thermostat designed for 240V water heaters, featuring a digital touch control and LED temperature display. Easy to install and backed by A.O. Smith’s trusted quality, it ensures precise temperature management and reliable performance for your home’s hot water needs. ## Description Product Description Reliance 9000509-045 Single Element Electric Thermostat From the Manufacturer Single element electric water heater thermostat Review: Perfect replacement - Product was as described, easy to install, wired it in, has been working like a charm. I’m very thorough in my work, it only took about 15, 20 minutes. Review: Works perfect - Easy to install. TURN OFF POWER first! Just a few wires and it was done. ## Features - Thermostat - For Use With Single Element Electric Water Heaters - Brand Name: Ao Smith - Model Number: 9000509-045 ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000DZDUVS | | Additional Features | Temperature Display | | Backlight | No | | Best Sellers Rank | #393,094 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #982 in Water Heater Replacement Parts | | Brand | A. O. Smith | | Brand Name | A. O. Smith | | Color | Black | | Connectivity Protocol | BACnet MS/TP | | Connectivity Technology | Wired | | Control Method | Touch | | Control Type | Touch Control | | Controller Type | Touch Control | | Customer Reviews | 4.6 out of 5 stars 144 Reviews | | Display Type | LED | | Global Trade Identification Number | 00020363105488 | | Included Components | Reliance 9000509-045 Single Element Electric Thermostat | | Item Type Name | Reliance 9000509-045 Single Element Electric Thermostat | | Item Weight | 0.3 Pounds | | Manufacturer | Reliance | | Manufacturer Part Number | 9000509-045 | | Manufacturer Warranty Description | Warranty. | | Material Type | Plastic | | Model Name | Reliance 9000509-045 Single Element Electric Thermostat | | Model Number | 9000509-045 | | Mounting Type | Wall Mount | | Power Source | Corded Electric | | Shape | Rectangular | | Special Feature | Temperature Display | | Specific Uses For Product | Single Element Electric Water Heaters | | Temperature Control Type | Digital | | UPC | 020363105488 | | Unit Count | 1.0 Count | | Voltage | 240 Volts | ## Product Details - **Brand:** A. O. Smith - **Color:** Black - **Controller Type:** Touch Control - **Model Name:** Reliance 9000509-045 Single Element Electric Thermostat - **Specific Uses For Product:** Single Element Electric Water Heaters ## Images ![Reliance 9000509-045 Single Element Electric Thermostat - Image 1](https://m.media-amazon.com/images/I/6196vXJIYEL.jpg) ## Questions & Answers **Q: what are the 2 round circle,s on the back for?** A: This answer is incorrect, they are temperature sensors that set against the tank **Q: what are the 2 round on the back for?** A: If you're talking about the button looking metal circles, they are what senses the tanks temperature. One for the control thermostat, the other for the over temp. Hope this helps. **Q: I have a 10 gal reliance 501 water heater with a WH7 upper switch. It looks like this one, Reliance 9000509-045, but size does not match** A: It may work provided the voltage and number of elements are the same but if the part numbers are different then I wouldn't advise substitution without consulting an expert, which I am not. Sorry I can't be of more help. **Q: Can I use this for a 240 V single element water heater? Is it rated for 125 or 240 V, or does that even matter?** A: As far as I know, this thermostat is intended for 220-240 volt single element water heaters. I don't know if it will work on 110-125 volt water heaters. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Perfect replacement *by M***F on June 26, 2025* Product was as described, easy to install, wired it in, has been working like a charm. I’m very thorough in my work, it only took about 15, 20 minutes. ### ⭐⭐⭐⭐⭐ Works perfect *by M***R on January 23, 2024* Easy to install. TURN OFF POWER first! Just a few wires and it was done. ### ⭐⭐⭐⭐ Replacement thermostat on Sears water heater works fine. *by E***D on October 2, 2014* As described. Identical (same mfg and part number) to the original Sears thermostat. Included the clear plastic safety cover. The temperature control knob is shorter than original, and requires small screw driver to adjust. Could not use a push-in wire connect as the square washers were omitted. Just curved the wire around the screws to connect. Has been working OK. ## Frequently Bought Together - AO Smith Reliance 9000509-045 Single Element Electric Thermostat, Pack of 1, Black - Camco 09883 5" Residential Screw-In Water Heater Element Wrench, Multi, Single Unit - Camco 1500W 120V Water Heater Element | Screw-In Type | Low Watt Density (02463) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hk/products/4147562-reliance-9000509-045-single-element-electric-thermostat](https://www.desertcart.hk/products/4147562-reliance-9000509-045-single-element-electric-thermostat) --- *Product available on Desertcart Hong Kong* *Store origin: HK* *Last updated: 2026-07-21*