Vaillant Diaphragm 01-0320 New Type 0020107707

Mag 125/7

The Vaillant Diaphragm 01-0320 (New Type 0020107707) is a genuine OEM replacement component designed for use in Vaillant combination boilers. This diaphragm is a critical part of the water section or diverter valve assembly, where it regulates water pressure and flow to ensure consistent heating and hot water delivery.

Manufactured from high-quality, heat- and pressure-resistant elastomer, this updated diaphragm design provides improved flexibility, durability, and sealing performance. The new type (0020107707) supersedes the older 01-0320 version, ensuring compatibility with a wide range of Vaillant boiler models.

Key Features

• Genuine Vaillant diaphragm – Part No. 01-0320 (New Type 0020107707)

• Regulates water flow and system pressure in combination boilers

• Updated design offers improved durability and flexibility

• Made from heat- and pressure-resistant rubber material

• Prevents loss of hot water or boiler lockout due to diaphragm wear

• OEM-quality replacement for perfect fit and reliable operation

• Easy to install – ideal for servicing or hydraulic maintenance

• Maintains consistent performance and efficiency

Compatibility

• Suitable for a wide range of Vaillant ecoMAX, VCW, TURBOmax, and Mag boilers

• Replaces older diaphragm version 01-0320

• Used in diverter valve and hydraulic block assemblies

• For domestic combination boiler applications

When to Replace

• If the boiler fails to produce hot water or loses pressure

• When the existing diaphragm becomes brittle, cracked, or stretched

• During boiler servicing or diverter valve overhaul

Technical Specifications

• Manufacturer: Vaillant

• Old Part Number: 01-0320

• New Part Number: 0020107707

• Component Type: Water section diaphragm

• Material: Heat- and pressure-resistant elastomer

• Function: Controls hydraulic flow between heating and hot water systems

• Application: Domestic Vaillant combination boilers