---
product_id: 13825104
title: "Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3"
brand: "watts"
price: "KD 97.72"
currency: KWD
in_stock: false
reviews_count: 10
url: https://www.desertcart.com.kw/products/13825104-watts-automatic-fill-valve-for-hot-water-boiler-b911s-m3
store_origin: KW
region: Kuwait
---

# Quick fill & purge 1/2" inlet Backflow preventor Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3

**Brand:** watts
**Price:** KD 97.72
**Availability:** ❌ Out of Stock

## Summary

> 🔥 Elevate Your Heating Game with Watts!

## Quick Answers

- **What is this?** Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 by watts
- **How much does it cost?** KD 97.72 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.com.kw](https://www.desertcart.com.kw/products/13825104-watts-automatic-fill-valve-for-hot-water-boiler-b911s-m3)

## Best For

- watts enthusiasts

## Why This Product

- Trusted watts brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Quick & Efficient:** Experience rapid system filling and purging.
- • **Dual Functionality:** Combines pressure regulation and backflow prevention.
- • **Robust Bronze Build:** Durable construction for long-lasting performance.
- • **Versatile Connections:** Compatible with 1/2" union solder inlet and NPT threaded outlet.
- • **Effortless System Management:** Streamline your boiler feed lines with ease.

## Overview

The Watts Automatic Fill Valve B911S-M3 is designed for hydronic heating systems, providing a combination of feed water pressure regulation and backflow prevention. Its all-bronze construction ensures durability, while the 1/2 inch union solder inlet and NPT threaded outlet make installation a breeze. Enjoy quick system filling and purging for optimal performance.

## Description

Watts B911S-M3 Automatic Fill Valve for Hot Water Boiler is a combination fill valve and backflow preventer for use in the boiler feed lines in commercial and residential hydronic heating systems. It provides make-up water to the boiler and prevents backflow when supply pressure falls below system pressure. It consists of a bronze backflow preventer (Model 9D) and a bronze feed water pressure regulator (Model 1156F) in a single pre-assembled unit. The high capacity fill valve provides quick system filling and purging. Size is 1/2 in. union solder inlet x NPT threaded outlet connections. The maximum pressure is 100 psi.

## Features

- For use in boiler feed lines in hydronic heating systems
- Combination feed water pressure regulator and backflow preventor
- Quick system filling and purging
- All bronze construction
- 1/2 in. union solder inlet x NPT threaded outlet connection

## Product Details

- **Material:** Bronze
- **Brand:** Watts
- **Item dimensions L x W x H:** 9.6 x 0.1 x 10.8 inches
- **Exterior Finish:** Bronze
- **Inlet Connection Size:** 0.5 Inches
- **Inlet Connection Type:** National Pipe Tapered
- **Outlet Connection Type:** FNPT
- **Number of Ports:** 2
- **Outlet Connection Size:** 0.5 Inches
- **Specification Met:** Asse 1012

## Images

![Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 - Image 1](https://m.media-amazon.com/images/I/51ofuUYWt1L.jpg)
![Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 - Image 2](https://m.media-amazon.com/images/I/412lFGEo1+L.jpg)
![Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 - Image 3](https://m.media-amazon.com/images/I/71hXaHbT76L.jpg)
![Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 - Image 4](https://m.media-amazon.com/images/I/71R2tXNxwaL.jpg)
![Watts Automatic Fill Valve for Hot Water Boiler, B911S-M3 - Image 5](https://m.media-amazon.com/images/I/815EXhuFqzL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars







  
  
    Easy to install
  

*by E***M on Reviewed in the United States on September 3, 2023*

It does what it's supposed to do it regulates the water pressure to my heating unit

### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars







  
  
    It works! Well-built, easy install.
  

*by R***N on Reviewed in the United States on July 16, 2018*

It works! Well-built, easy install. What more can I say?

### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars







  
  
    Was lucky to find this part.
  

*by A***L on Reviewed in the United States on April 8, 2022*

I could never fathom paying so much for a part, but when you need it, you need it and I'm glad it was available.

---

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**Shop now:** [https://www.desertcart.com.kw/products/13825104-watts-automatic-fill-valve-for-hot-water-boiler-b911s-m3](https://www.desertcart.com.kw/products/13825104-watts-automatic-fill-valve-for-hot-water-boiler-b911s-m3)

---

*Product available on Desertcart Kuwait*
*Store origin: KW*
*Last updated: 2026-01-28*