--- product_id: 125395150 title: "Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length" brand: "willhi" price: "FREE" currency: ARS in_stock: false reviews_count: 2 url: https://www.desertcart.com.ar/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v store_origin: AR region: Argentina --- # 30A heavy-duty relay output 3m extended sensor cable Β±0.2% RH ultra-precise measurement Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length **Brand:** willhi **Price:** FREE **Availability:** ❌ Out of Stock ## Summary > πŸ’§ Command Your Climate Like a Pro β€” Precision Humidity Control, Elevated. ## Quick Answers - **What is this?** Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length by willhi - **How much does it cost?** FREE with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.com.ar](https://www.desertcart.com.ar/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v) ## Best For - willhi enthusiasts ## Why This Product - Trusted willhi brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Sensor Freedom:** Extra-long 3-meter sensor leads let you place the sensor exactly where it matters mostβ€”no compromises. - β€’ **Powerhouse Relay:** 30A heavy-duty relay supports high-capacity humidifiers and dehumidifiers without breaking a sweat. - β€’ **Crystal-Clear Display:** Ultra-bright 3-digit LED ensures you’re always in the know, with sleek panel-mount clips for a professional finish. - β€’ **Smart Programmability:** Customize control ranges, calibrations, delays, and alarms to fit your unique climate needs effortlessly. - β€’ **Precision Control Mastery:** Maintain perfect humidity with Β±0.2% RH accuracy and 3% control range for flawless environment tuning. ## Overview The WH8040 Digital Air Humidity Controller by Willhi delivers ultra-precise humidity measurement (Β±0.2% RH) and control across 0-99% RH. Featuring a robust 30A relay for high-power HVAC equipment, a 3-meter sensor cable for flexible placement, and a bright 3-digit LED display, it offers advanced programmability including calibration, delay, and alarm functions. Designed for professional environments demanding reliable, customizable humidity management. ## Description This is the ultra-reliable WH8040 humidity controller with HM-40 capacitive RH sensor. These controllers were specially ordered from Willhi's factory with 30A output relay and extra-long (3m) sensor leads for use with high power humidification / dehumidification equipment. ## Features - Humidity measurement (+/- 0.2% RH) and control (3% RH) from 0 to 99% RH - 110 vac input with heavy-duty 30A output relay - Extra long (3m / 9ft) sensor leads; Miniature HM-40 humidity sensor with temperature compensation - Multiple programmable functions including control range, calibration, on/off delays, lower and upper limits and alarms. - Ultra-bright 3 digit LED display; Includes adjustable mounting clips for panel mount ## Technical Specifications | Specification | Value | |---------------|-------| | Manufacturer | Willhi | | Part Number | WH8040110V 30A | | Item Weight | 10.1 ounces | | Package Dimensions | 4.5 x 3.5 x 2 inches | | Is Discontinued By Manufacturer | No | | Batteries Included? | No | | Batteries Required? | No | ## Images ![Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length - Image 1](https://m.media-amazon.com/images/I/81NXDmnTaJL.jpg) ![Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length - Image 2](https://m.media-amazon.com/images/I/91k69aQWKeL.jpg) ![Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length - Image 3](https://m.media-amazon.com/images/I/81Qq4SPzu3L.jpg) ![Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length - Image 4](https://m.media-amazon.com/images/I/112oWQkslyL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ It works perfectly and I love it. The instructions are hard to understand unfortunately *by A***R on Reviewed in the United States on April 6, 2018* It works perfectly and I love it. The instructions are hard to understand unfortunately. Please consult the internet for further help installing so you don't fry it if you don't understand. ### ⭐⭐⭐ I need help *by A***R on Reviewed in the United States on January 19, 2019* I cant figure out how to make this thing work. I've done the wiring properly but my humidity readout is always 10-15% higher than 2nd control sensor. Can anybody help? --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.com.ar/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v](https://www.desertcart.com.ar/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v) --- *Product available on Desertcart Argentina* *Store origin: AR* *Last updated: 2026-08-24*