14 Litre Resin
Hi-Flow 50 l/min
Large Households
22mm Install Kit Included
Metered Control
Unvented / Megaflow
Free BWT Commissioning
The BWT WS555 is the top-of-range hi-flow domestic water softener in the BWT WS series — combining the large 14-litre resin capacity of the WS355 with the 22mm high-flow performance of the WS455. Delivering a peak flow rate of 50 litres per minute and a maximum softened water capacity of 2500 litres between regenerations, the WS555 is the ideal choice for larger households, hard water areas, and high-flow plumbing systems where both flow rate and regeneration frequency are important. It is supplied complete with a 22mm installation kit as standard.
With a 14L resin volume, the WS555 regenerates less often than the WS455 (10L), resulting in lower overall salt and water consumption per period — making it the most efficient hi-flow option for larger households. Like all WS models it uses BWT's metered AMECS demand system, with free @Home commissioning and a 5-year parts / 2-year labour warranty.
2500L
max
Softened Capacity
💡 BWT WS Range Comparison — At a Glance
WS355: 14L resin, 30 l/min peak, 15mm kit — standard flow, conventional systems. WS455: 10L resin, 50 l/min peak, 22mm kit — hi-flow for modern/unvented systems, smaller resin. WS555: 14L resin, 50 l/min peak, 22mm kit — hi-flow AND large resin capacity, best for larger households or very hard water areas where infrequent regeneration is valued alongside high flow performance.
Key Features
💪 Large 14L Resin + 50 l/min Hi-FlowThe WS555 uniquely combines a 14L resin vessel (same as the standard-flow WS355) with the 50 l/min hi-flow capability of the 22mm connection system. This means fewer regeneration cycles for larger households while maintaining full flow performance for modern plumbing systems.
🚿 22mm Install Kit — All SystemsSupplied with a full 22mm stainless steel high-flow installation kit covering all system types: conventional vented, combi boiler, unvented (pressurised/Megaflow). No separate kit purchase required.
📊 2500 Litre Softened Water CapacityThe larger 14L resin holds up to 2500 litres of softened water capacity between regenerations (at 300ppm hardness). For a typical 4-person household using 200L/day, this means regeneration only every 12+ days — minimising disruption and running costs.
🧂 Efficient Salt UsageUses 0.6–2.0kg of salt per regeneration (vs 0.3–1.2kg for the WS455) — and because regenerations are less frequent with the larger 14L resin, overall monthly salt consumption is competitive with smaller models. Salt storage: 8kg block / 19kg tablet.
💧 Metered AMECS Demand ControlRegenerates only when the resin is actually exhausted, not on a fixed schedule. The AMECS controller adapts to daily usage patterns and retains settings for up to 72 hours during power failure.
🆓 Free @Home CommissioningFree BWT @Home commissioning service included — a BWT-trained engineer visits after installation to configure the softener and demonstrate operation. Book directly with BWT after purchase.
🏆 5 Year Parts / 2 Year LabourCovered by BWT's comprehensive warranty — 5 years parts and 2 years on-site labour. Register within 100 days of purchase to activate the full @Home warranty offer.
🔧 BWT Rotary Millennium ValveThe same reliable rotary valve system as across the WS range — minimal moving parts, maximum long-term reliability. All servicing via BWT engineers to maintain warranty.
Technical Specifications
| Specification |
WS555 Detail |
| Resin Volume |
14 litres |
| Dimensions (H × W × D) |
602mm × 270mm × 480mm |
| Min Flow Rate (Hi-Flo) |
10 l/min |
| Continuous Flow Rate (Hi-Flo) |
30 l/min |
| Peak Flow Rate (Hi-Flo) |
50 l/min |
| Basic Flow (@ 1 bar pressure loss) |
26 l/min |
| Max Pressure |
5 bar |
| Min Pressure |
1.7 bar |
| Max Water Temperature |
49°C |
| Inlet / Outlet Connection |
¾" BSP |
| Drain Connection |
½" tube |
| Installation Kit Included |
22mm stainless steel hoses and valves (Hi-Flow) |
| Salt per Regeneration |
0.6–2.0 kg (min/max) |
| Water per Regeneration |
<80 litres |
| Salt Storage |
8kg block / 19kg tablet |
| Max Softened Water Capacity |
2500 litres |
| Electrical Supply |
220V AC / 12V DC |
| Regeneration Type |
Metered demand (AMECS) |
| Unit Weight (empty / in service) |
22kg / 50kg |
| Warranty |
5 years parts / 2 years on-site labour |
| Brand |
BWT |
Frequently Asked Questions
Who is the WS555 designed for?
The WS555 is ideal for households of 6 or more, properties in very hard water areas (where the resin is exhausted more quickly), and any installation requiring both 22mm high-flow connections and a large resin capacity. The combination of 14L resin and 50 l/min flow makes it the most capable single-cabinet domestic softener in the BWT WS range.
Does the WS555 fit under a kitchen sink?
At 602mm high, 270mm wide and 480mm deep, the WS555 is the same footprint as the WS355 — designed to fit under a standard 600mm-deep kitchen sink cabinet. However, at 22kg empty and 50kg in service, it is a substantial unit, so the floor support beneath a kitchen unit should be confirmed adequate before installation.
Is the WS555 suitable as a commercial unit?
The WS555 is classified as a domestic water softener by BWT, and is described in some sources as "light commercial." It is well-suited to larger domestic properties and small commercial premises such as salon backwashes, small offices, and letting properties with multiple occupants. For heavy commercial or industrial demand, BWT offer dedicated commercial softener ranges.
⚠️ Note: WS555 supplied with 22mm hi-flow install kit. Requires an unsoftened drinking water tap as per Building Regulations Part G. Register within 100 days for the full BWT @Home warranty and free commissioning service. Best suited to larger households or hard water areas where high-flow and large resin volume are both required.
