Honeywell Home DU144 22mm Automatic Bypass Valve | Straight Pattern DU144A1001

The Honeywell Home DU144A1001 22mm Automatic Bypass Valve maintains minimum flow through boilers when TRVs close, preventing low flow alarms and flue gas condensation corrosion. Factory-set to 0.2 bar with adjustable range 0.1-0.6 bar, it ensures proper operation of boiler temperature sensors and external compensating controls.

Key Features

• 22mm compression fittings for straight pipe installation between flow and return.
• Adjustable differential pressure 0.1-0.6 bar (factory 0.2 bar) via knurled handwheel.
• Protection cap prevents unauthorised adjustment of settings.
• High flow capacity kvs 2.3 (cv 2.7) up to 1.5 m³/hour.
• Brass construction with stainless steel spindle and EPDM seals.
• Spanner flats assist compression fitting tightening.

Why Choose Honeywell DU144?

Essential safety device for modern condensing boilers requiring minimum flow protection, reducing system noise and ensuring reliable operation when most radiators are closed.

Superior to fixed bypass valves with precise pressure control and rugged industrial design.

Suitable For

• Condensing boilers specifying minimum flow requirements.
• Systems with TRVs where return temperature protection is needed.
• Gas water heaters requiring guaranteed minimum circulation.

Technical Specifications

• Brand: Honeywell Home by Resideo
• Model: DU144 Straight Automatic Bypass Valve
• MPN: DU144A1001
• Connections: 22mm compression (straight pattern)
• Medium: Water/glycol mix (VDI 2035 compliant)
• pH Range: 8-9.5
• Operating Temperature: 2-130 °C
• Maximum Pressure: 10 bar
• Differential Pressure: 0.1-0.6 bar (factory 0.2 bar)
• Flow Capacity: kvs 2.3 (cv 2.7)
• Materials: Brass body, stainless spindle, EPDM seals
• Dimensions: 79 x 80 x 60 mm (WxHxD)
• Weight: 0.3 kg
• Warranty: 1 year

Installation & Operation

Install between boiler flow and return with arrow indicating flow direction. Adjust handwheel to required differential pressure (typically 0.15-0.3 bar per boiler manual). Valve modulates automatically - closes when TRVs open (normal flow), opens progressively when TRVs close (restricting main circuit flow).