Off-Centre By-Pass Kit – Fixed 25 kPa for 662–665 Manifolds

Off-centre by-pass kit pre-set to 25 kPa (2,500 mm w.g.).
Designed for use with 662, 664, and 665 series distribution manifolds.

• Maximum working pressure: 10 bar

• Operating temperature range: -10°C to 110°C

Simplified Pressure Control: Off-Centre By-Pass Kit (25 kPa Fixed)

Improve the performance of your hydronic system with this factory-calibrated Off-Centre By-Pass Kit, fixed at 25 kPa (2,500 mm w.g.). Engineered to maintain a constant pressure differential, it protects circulation pumps and zone valves while ensuring uninterrupted flow when heating circuits close.

Fully compatible with 662, 664, and 665 series distribution manifolds, it serves as an essential component for maintaining stable and efficient heating operation.

Smart Compatibility with Proven Manifolds

Specifically developed for direct installation with Caleffi 662, 664, and 665 series manifolds, this kit removes the need for field adjustments thanks to its factory-set configuration.

The off-centre layout optimizes space and enables flexible installation, even within compact manifold cabinets.

With a maximum working pressure of 10 bar and an operating temperature range from -10°C to 110°C, it is built to meet the performance requirements of modern radiant and hydronic heating systems.

Reliable Performance & System Protection

In the absence of a dependable by-pass, pressure build-up may cause noise, system stress, and energy inefficiency. This pre-set 25 kPa unit helps maintain hydraulic balance, reduces component wear, and supports long-term system durability.

Suitable for underfloor heating systems, multi-zone applications, and energy-efficient installations.

Durable construction. Straightforward installation. A dependable solution for comfort and performance.