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Automatic Bypass Valve 22mm Angled and Straight — Central Heating Bypass for TRV Systems
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Automatic Bypass Valve 22mm Angled and Straight — Central Heating Bypass for TRV Systems

Automatic Bypass Valve 22mm Angled and Straight — Central Heating Bypass for TRV Systems

The BPV100 / BPV100S Automatic Bypass Valve is a pressure-operated bypass valve for 22mm central heating pipework, designed to maintain a minimum flow rate through the boiler when thermostatic radiator valves (TRVs) close down. Available in two configurations: BPV100 (angled) — for fitting between parallel flow and return connections at a corner — and BPV100S (straight) — for in-line fitting on a straight pipework run. The valve opens automatically when system differential pressure rises beyond the set point, routing water through the bypass to prevent the boiler from firing against a closed or near-closed circuit. This eliminates pump noise, reduces system pressure spikes, and protects the boiler heat exchanger — all without any electrical connection or programmer input.

⚡ BPV100 vs BPV100S — Which to choose?
BPV100 (angled): The inlet and outlet ports are at 90° to each other — ideal for fitting between the flow and return where the pipes run along parallel walls, or in a tight corner adjacent to the boiler. This is the most commonly used configuration.
BPV100S (straight): The inlet and outlet are in-line — for fitting on a dedicated bypass spur connected in parallel between a straight section of the flow and return pipework. Used where the flow and return run alongside each other and a short cross-connection bridge is required.
Features & Benefits
✔ Pressure-Operated — No Electrical Connection
The BPV100 is entirely mechanical — it responds to the actual differential pressure in the system and opens or closes accordingly. There is no wiring, no controls interface, no programmer setting required. It operates correctly regardless of boiler type, control strategy, or zone configuration, making it straightforward to specify and install in any domestic or light commercial CH system.
✔ Protects Boiler Heat Exchanger
Many boiler manufacturers specify a minimum flow rate through the heat exchanger regardless of system load — if all TRVs close simultaneously, the pump circulates water around a closed circuit, pressure rises sharply, flow drops to near zero, and the heat exchanger overheats. The BPV100 prevents this by providing a bypass path that maintains flow. This is a warranty-critical requirement for many modern condensing boilers, particularly those with small-volume primary heat exchangers.
✔ Eliminates System Noise from TRVs
As TRVs close down, the increased flow resistance can cause pipe noise, kettling, and pump whine. The BPV100 opens progressively as pressure rises, maintaining a stable system pressure and preventing the pressure surges that cause noise in pipework and boiler components. For end-users, this is often the most immediately noticeable benefit of installation.
✔ Compact — Easy to Retrofit
At 105 × 50 × 20mm, the BPV100 is slim enough to fit in tight spaces adjacent to the boiler, in airing cupboards, or on manifold pipework. Standard 22mm compression fittings mean no specialist tools or pipe preparation beyond a standard compression fitting — suitable for retrofit on existing systems without draining down provided isolation valves are present.
Technical Specifications
Part Numbers BPV100 (angled) / BPV100S (straight)
Connection Size 22mm compression
Operation Type Pressure-operated (no electrical connection)
Configuration BPV100: angled (90° inlet/outlet) · BPV100S: straight (in-line)
Application CH systems with TRVs; boiler bypass; zone valve systems
Dimensions (W × H × D) 105 × 50 × 20 mm
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From $7.09

Original: $20.25

-65%
Automatic Bypass Valve 22mm Angled and Straight — Central Heating Bypass for TRV Systems—

$20.25

$7.09

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Automatic Bypass Valve 22mm Angled and Straight — Central Heating Bypass for TRV Systems

The BPV100 / BPV100S Automatic Bypass Valve is a pressure-operated bypass valve for 22mm central heating pipework, designed to maintain a minimum flow rate through the boiler when thermostatic radiator valves (TRVs) close down. Available in two configurations: BPV100 (angled) — for fitting between parallel flow and return connections at a corner — and BPV100S (straight) — for in-line fitting on a straight pipework run. The valve opens automatically when system differential pressure rises beyond the set point, routing water through the bypass to prevent the boiler from firing against a closed or near-closed circuit. This eliminates pump noise, reduces system pressure spikes, and protects the boiler heat exchanger — all without any electrical connection or programmer input.

⚡ BPV100 vs BPV100S — Which to choose?
BPV100 (angled): The inlet and outlet ports are at 90° to each other — ideal for fitting between the flow and return where the pipes run along parallel walls, or in a tight corner adjacent to the boiler. This is the most commonly used configuration.
BPV100S (straight): The inlet and outlet are in-line — for fitting on a dedicated bypass spur connected in parallel between a straight section of the flow and return pipework. Used where the flow and return run alongside each other and a short cross-connection bridge is required.
Features & Benefits
✔ Pressure-Operated — No Electrical Connection
The BPV100 is entirely mechanical — it responds to the actual differential pressure in the system and opens or closes accordingly. There is no wiring, no controls interface, no programmer setting required. It operates correctly regardless of boiler type, control strategy, or zone configuration, making it straightforward to specify and install in any domestic or light commercial CH system.
✔ Protects Boiler Heat Exchanger
Many boiler manufacturers specify a minimum flow rate through the heat exchanger regardless of system load — if all TRVs close simultaneously, the pump circulates water around a closed circuit, pressure rises sharply, flow drops to near zero, and the heat exchanger overheats. The BPV100 prevents this by providing a bypass path that maintains flow. This is a warranty-critical requirement for many modern condensing boilers, particularly those with small-volume primary heat exchangers.
✔ Eliminates System Noise from TRVs
As TRVs close down, the increased flow resistance can cause pipe noise, kettling, and pump whine. The BPV100 opens progressively as pressure rises, maintaining a stable system pressure and preventing the pressure surges that cause noise in pipework and boiler components. For end-users, this is often the most immediately noticeable benefit of installation.
✔ Compact — Easy to Retrofit
At 105 × 50 × 20mm, the BPV100 is slim enough to fit in tight spaces adjacent to the boiler, in airing cupboards, or on manifold pipework. Standard 22mm compression fittings mean no specialist tools or pipe preparation beyond a standard compression fitting — suitable for retrofit on existing systems without draining down provided isolation valves are present.
Technical Specifications
Part Numbers BPV100 (angled) / BPV100S (straight)
Connection Size 22mm compression
Operation Type Pressure-operated (no electrical connection)
Configuration BPV100: angled (90° inlet/outlet) · BPV100S: straight (in-line)
Application CH systems with TRVs; boiler bypass; zone valve systems
Dimensions (W × H × D) 105 × 50 × 20 mm

Product Information

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Description

The BPV100 / BPV100S Automatic Bypass Valve is a pressure-operated bypass valve for 22mm central heating pipework, designed to maintain a minimum flow rate through the boiler when thermostatic radiator valves (TRVs) close down. Available in two configurations: BPV100 (angled) — for fitting between parallel flow and return connections at a corner — and BPV100S (straight) — for in-line fitting on a straight pipework run. The valve opens automatically when system differential pressure rises beyond the set point, routing water through the bypass to prevent the boiler from firing against a closed or near-closed circuit. This eliminates pump noise, reduces system pressure spikes, and protects the boiler heat exchanger — all without any electrical connection or programmer input.

⚡ BPV100 vs BPV100S — Which to choose?
BPV100 (angled): The inlet and outlet ports are at 90° to each other — ideal for fitting between the flow and return where the pipes run along parallel walls, or in a tight corner adjacent to the boiler. This is the most commonly used configuration.
BPV100S (straight): The inlet and outlet are in-line — for fitting on a dedicated bypass spur connected in parallel between a straight section of the flow and return pipework. Used where the flow and return run alongside each other and a short cross-connection bridge is required.
Features & Benefits
✔ Pressure-Operated — No Electrical Connection
The BPV100 is entirely mechanical — it responds to the actual differential pressure in the system and opens or closes accordingly. There is no wiring, no controls interface, no programmer setting required. It operates correctly regardless of boiler type, control strategy, or zone configuration, making it straightforward to specify and install in any domestic or light commercial CH system.
✔ Protects Boiler Heat Exchanger
Many boiler manufacturers specify a minimum flow rate through the heat exchanger regardless of system load — if all TRVs close simultaneously, the pump circulates water around a closed circuit, pressure rises sharply, flow drops to near zero, and the heat exchanger overheats. The BPV100 prevents this by providing a bypass path that maintains flow. This is a warranty-critical requirement for many modern condensing boilers, particularly those with small-volume primary heat exchangers.
✔ Eliminates System Noise from TRVs
As TRVs close down, the increased flow resistance can cause pipe noise, kettling, and pump whine. The BPV100 opens progressively as pressure rises, maintaining a stable system pressure and preventing the pressure surges that cause noise in pipework and boiler components. For end-users, this is often the most immediately noticeable benefit of installation.
✔ Compact — Easy to Retrofit
At 105 × 50 × 20mm, the BPV100 is slim enough to fit in tight spaces adjacent to the boiler, in airing cupboards, or on manifold pipework. Standard 22mm compression fittings mean no specialist tools or pipe preparation beyond a standard compression fitting — suitable for retrofit on existing systems without draining down provided isolation valves are present.
Technical Specifications
Part Numbers BPV100 (angled) / BPV100S (straight)
Connection Size 22mm compression
Operation Type Pressure-operated (no electrical connection)
Configuration BPV100: angled (90° inlet/outlet) · BPV100S: straight (in-line)
Application CH systems with TRVs; boiler bypass; zone valve systems
Dimensions (W × H × D) 105 × 50 × 20 mm