---
product_id: 125395150
title: "Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length"
brand: "willhi"
price: "₨153"
currency: SCR
in_stock: false
reviews_count: 2
url: https://www.desertcart.sc/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v
store_origin: SC
region: Seychelles
---

# 30A heavy-duty relay output 3m extended sensor cable ±0.2% RH ultra-precise measurement Digital Air Humidity Controller WH8040 1%~99% RH, AC 110V, 30A Relay, 3m sensor length

**Brand:** willhi
**Price:** ₨153
**Availability:** ❌ Out of Stock

## Summary

> 💧 Command Your Climate Like a Pro — 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?** ₨153 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.sc](https://www.desertcart.sc/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

- • **Sensor Freedom:** Extra-long 3-meter sensor leads let you place the sensor exactly where it matters most—no compromises.
- • **Powerhouse Relay:** 30A heavy-duty relay supports high-capacity humidifiers and dehumidifiers without breaking a sweat.
- • **Crystal-Clear Display:** Ultra-bright 3-digit LED ensures you’re always in the know, with sleek panel-mount clips for a professional finish.
- • **Smart Programmability:** Customize control ranges, calibrations, delays, and alarms to fit your unique climate needs effortlessly.
- • **Precision Control Mastery:** Maintain perfect humidity with ±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 (±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?

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**Shop now:** [https://www.desertcart.sc/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v](https://www.desertcart.sc/products/125395150-digital-air-humidity-controller-wh8040-1-99-rh-ac-110v)

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*Product available on Desertcart Seychelles*
*Store origin: SC*
*Last updated: 2026-02-06*