WaterBoost WB-INT Slimline 500 Variable Speed 2409310

The WaterBoost WB-INT Slimline 500 is the larger sibling of the WB-INT Slimline 300 — a complete, pre-assembled variable-speed boosting system combining a 500-litre WRAS-approved upright slimline tank with the DAB Esybox Diver internal pump. Designed for 3–5 bedroom homes with high daily demand or a slow-filling mains supply, it delivers up to 100 l/min at up to 5 bar.

The Esybox Diver sits submerged inside the tank itself — there is no external pump unit — making this one of the most compact and quiet boosting systems available. The mains connects directly via the pre-fitted ¾” ball float valve. Built-in WiFi links to the DConnect app for remote monitoring and works with Google Home and Amazon Alexa.

At 700mm diameter × 1500mm high, the tank fits into a standard utility room, garage, or under-stair space. Fully pre-assembled — no site build required. 5-year tank warranty and 3-year DAB pump warranty. Please contact us for delivery timescales.

Which should I choose?

WB-INT Slimline 500 — the best overall choice at £1,117.75 + VAT. More storage (500L vs 450L), higher max flow (100 l/min vs 80), higher max pressure (5 bar vs 3 bar), WiFi and voice control, named 5yr tank + 3yr pump warranties — at £227.25 less than the Powertank Variable Speed.

Powertank SLIMLINE 450 Fixed — lowest cost at £818.55 + VAT. Choose if Fluid Category 4 is required and flow demand is modest (40 l/min). 450L storage.

Powertank SLIMLINE 450 Variable — 80 l/min variable speed with Fluid Category 4 compliance, but at £1,345 + VAT — £227.25 more than the WB-INT with 50L less storage, lower max pressure, and no WiFi. Choose only if Fluid Category 4 is a firm requirement.

How much does it cost and how is it delivered?

£1,117.75 + VAT (£1,341.30 inc VAT). Please contact us via WhatsApp or phone for delivery timescales on this product.

What is the difference between the 300L and 500L versions?

Both use the same DAB Esybox Diver pump with identical performance (100 l/min, 5 bar). The difference is purely storage: the 300L (£1,027.75 + VAT, 600mm × 1200mm) suits properties with moderate daily demand or a reasonable mains fill rate. The 500L (£1,117.75 + VAT, 700mm × 1500mm) is the better choice for very high-demand properties or a very slow mains supply where maximum overnight buffer storage is important.

What is the Esybox Diver and why is it inside the tank?

The Esybox Diver is a variable speed pump designed specifically to operate submerged inside the storage tank. This eliminates the need for a separate external pump unit, keeps the total footprint to the tank’s 700mm diameter, and naturally reduces operating noise. It includes built-in WiFi, DConnect app, Google Home, and Alexa connectivity.

How does the mains connection work?

The mains supply connects directly to the tank via the pre-fitted ¾” ball float valve. The tank fills automatically. The Esybox Diver draws from the tank and boosts pressure throughout the property. A minimum of 0.5 bar incoming pressure is required.

How does the WiFi and voice control work?

The Esybox Diver connects to the DConnect app via built-in WiFi for remote monitoring and pressure control. It integrates with Google Home and Amazon Alexa — “Hey Google, power shower” to boost pressure, or “Hey Google, sleep mode” to quieten it at night.

What warranties are included?

5 years on the WRAS slimline tank and 3 years DAB manufacturer warranty on the Esybox Diver pump, when purchased from Anglian Pumping Services.