---
product_id: 64483997
title: "Vaillant 178978 Valve Coupling 3 Way, MS, Includes Bypass Hydro Sheet"
brand: "vaillant"
price: "€ 425.50"
currency: EUR
in_stock: true
reviews_count: 1
url: https://www.desertcart.gr/products/64483997-vaillant-178978-valve-coupling-3-way-ms-includes-bypass-hydro
store_origin: GR
region: Greece
---

# Compact 16.2x10.6x7.6 cm design, lightweight 358g Integrated bypass for seamless system efficiency 3-way valve coupling for precise flow control Vaillant 178978 Valve Coupling 3 Way, MS, Includes Bypass Hydro Sheet

**Brand:** vaillant
**Price:** € 425.50
**Availability:** ✅ In Stock

## Summary

> ⚙️ Elevate your heating game with precision and efficiency!

## Quick Answers

- **What is this?** Vaillant 178978 Valve Coupling 3 Way, MS, Includes Bypass Hydro Sheet by vaillant
- **How much does it cost?** € 425.50 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/64483997-vaillant-178978-valve-coupling-3-way-ms-includes-bypass-hydro)

## Best For

- vaillant enthusiasts

## Why This Product

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

## Key Features

- • **Compact & Lightweight:** Designed for easy installation without bulk or weight concerns
- • **Reliable Compatibility:** Fits multiple Vaillant models like VC 104/4 – 7 and VC 126/3-5
- • **Maintenance Made Simple:** Durable MS construction reduces wear and extends system life
- • **Precision Flow Management:** 3-way valve coupling ensures optimal heating system performance
- • **Seamless System Integration:** Includes bypass hydro sheet for uninterrupted operation

## Overview

The Vaillant 178978 Valve Coupling 3 Way (MS) is a compact, lightweight priority switch valve designed for seamless integration with various Vaillant boiler models. Featuring a built-in bypass hydro sheet, it ensures efficient flow control and system reliability, making it an essential upgrade for professional-grade heating systems.

## Description



## Features

- Priority Switch Valve (MS, with bypass)
- For VC 104/4 – 7, VC 126/3-5, etc.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0017VD83C |
| Batteries Required? | No |
| Batteries included? | No |
| Customer Reviews | 3.0 3.0 out of 5 stars (1) |
| Date First Available | 22 Sept. 2011 |
| Item Package Quantity | 1 |
| Item Weight | 358 g |
| Item model number | 178978 |
| Manufacturer | Vaillant |
| Package Dimensions | 16.2 x 10.6 x 7.6 cm; 358.34 g |
| Part Number | 178978 |

## Images

![Vaillant 178978 Valve Coupling 3 Way, MS, Includes Bypass Hydro Sheet - Image 1](https://m.media-amazon.com/images/I/71QP8CdZRsL.jpg)

## Customer Reviews

### ⭐⭐⭐ 3.0 out of 5 stars







  
  
    Three Stars
  

*by M***H on Reviewed in the United Kingdom on 4 June 2015*

Arrived before expected date & the correct product even though Vaillant have modified it somewhat.

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**Shop now:** [https://www.desertcart.gr/products/64483997-vaillant-178978-valve-coupling-3-way-ms-includes-bypass-hydro](https://www.desertcart.gr/products/64483997-vaillant-178978-valve-coupling-3-way-ms-includes-bypass-hydro)

---

*Product available on Desertcart Greece*
*Store origin: GR*
*Last updated: 2026-05-25*