WaterBoost WB-EXT Slimline 500 Mini3 Variable Speed 2503210

WaterBoost WB-EXT Slimline 500 Mini3 Variable Speed 2503210 - Image 4

WaterBoost WB-EXT Slimline 500 Mini3 Variable Speed 2503210 - Image 5

Established 1975
Trusted by thousands of customers

The WaterBoost WB-EXT Slimline 500 Mini3 is a high-storage variable-speed water boosting system for 3–5 bedroom homes. A 500-litre WRAS-approved slimline tank (700mm dia × 1500mm high) pairs with the DAB Esybox Mini3 external variable speed pump, delivering 50 l/min at 3 bar with WiFi, DConnect app, and Google Home and Alexa voice control.

The Esybox Mini3 sits alongside the tank rather than inside it — keeping the pump fully accessible for servicing and maintenance at any time. The tank connects directly to the mains via the pre-fitted ¾” ball float valve, and the system arrives fully pre-built with no site assembly required.

Supplied with union connections, ¾” ball float valve, 600mm hose, and By-law 30 kit. The tank carries a 5-year warranty and the DAB Esybox Mini3 a 3-year warranty. Please contact us for delivery timescales.

50l/min

@ 3 bar

500L

Tank storage

45dB(A)

Ultra quiet

3yr

Pump warranty

WiFi · Google · Alexa
WRAS tank & pump
Variable speed
5.5 bar max
Direct mains
5yr tank warranty

Full Description

More about this product

Full Description

Product overview

The WaterBoost WB-EXT Slimline 500 Mini3 is the larger sibling of the WB-EXT 300 Mini3 — a complete, pre-built variable-speed boosting system for 3–5 bedroom homes with high daily demand or a slow-filling mains supply. A 500-litre WRAS-approved slimline tank (700mm dia × 1500mm high) pairs with the DAB Esybox Mini3 external variable speed pump, delivering 50 l/min at 3 bar and up to 5.5 bar maximum.

The Esybox Mini3 sits alongside the tank — fully accessible for servicing and maintenance at any time — running at a quiet 45 dB(A). WiFi via the DConnect app enables remote pressure monitoring and control, with Google Home and Alexa voice commands included. The mains connects directly via the pre-fitted ¾” ball float valve. Fully pre-built — no site assembly required.

Includes union connections, ¾” ball float valve, 600mm hose, and By-law 30 kit. 5-year tank warranty and 3-year DAB pump warranty. Please contact us for delivery timescales.

50^l/min

Flow @ 3 bar

500^L

Tank storage

5.5^bar

Max pressure

45^dB

Noise (1m)

WRAS tank & pump · Direct mains · Pre-assembled

What’s included

DAB Esybox Mini3 pump

External variable speed pump — sits alongside the tank. 50 l/min @ 3 bar, 5.5 bar max, 45 dB(A), WiFi via DConnect app, Google Home, Alexa. Pre-fitted plug. 3-year DAB warranty.

500L slimline tank

WRAS-approved 500-litre upright slimline tank — 700mm dia × 1500mm high. Direct mains via ¾” ball float valve. Includes 600mm hose, 2× union connections, 1″ pre-fitted tank outlet, By-law 30 kit. 5-year warranty.

Key features

500L maximum buffer storage

Largest storage in the WB-EXT Mini3 range — fills overnight on even a very slow mains supply, ready for peak demand.

50 l/min @ 3 bar — variable speed

Esybox Mini3 adjusts continuously to match demand — stable pressure, lower energy use than fixed speed, up to 5.5 bar maximum.

WiFi and voice control

DConnect app for remote monitoring and control. Google Home and Alexa — “Hey Google, power shower” or “sleep mode” at night.

External pump — easy servicing

Mini3 sits alongside the tank — fully accessible for inspection or replacement without any tank disturbance. Runs at 45 dB(A).

WRAS approved — potable water

Both tank and pump carry WRAS approval — fully compliant for potable water use in the UK.

Direct mains connection

Tank fills automatically via the pre-fitted ¾” ball float valve. Minimum 0.5 bar incoming pressure required.

Fully pre-built

Arrives ready to install — no site assembly required. Includes union connections, ¾” ball float valve, 600mm hose, and By-law 30 kit.

5yr tank + 3yr pump warranty

5-year warranty on the WRAS slimline tank and 3-year DAB warranty on the Esybox Mini3 pump.

Need higher flow?

The WB-EXT Slimline 500 Esybox (£1,084 + VAT) steps up to 80 l/min with the full DAB Esybox pump. The WB-INT Slimline 500 Variable (£1,117.75 + VAT) provides 100 l/min internally.

Typical applications

3–5 bedroom homes with slow mains

500L fills overnight even on the slowest mains trickle — ready with maximum buffer for peak morning and evening demand.

High daily demand properties

Where high household usage throughout the day requires a larger reserve to maintain consistent pressure at all outlets.

Where pump access matters

External pump is always accessible — ideal where the installation space makes internal pump maintenance difficult.

Garages, utility rooms, plant rooms

700mm diameter fits in standard domestic spaces. Pre-assembled and practical to site in a dedicated utility area.

Smart home integration

WiFi, DConnect app, Google Home, and Alexa — remote monitoring and voice control for pressure management throughout the day.

New and existing properties

Pre-assembled and straightforward to site — suitable for both new builds and retrofits in existing properties.

Technical specifications

DAB Esybox Mini3 pump

Flow rate	50 l/min @ 3 bar
Max pressure	5.5 bar
Pump type	Variable speed — external
Noise	45 dB(A) at 1m
Connectivity	WiFi — DConnect, Google, Alexa
Supply	240V, 50Hz — pre-fitted plug
WRAS	Yes
Warranty	3 years (DAB)

Slimline tank

Capacity	500 litres
Dimensions (dia × H)	700mm × 1500mm
Mains inlet	Direct — ¾” BSP ball float valve
WRAS	Yes — WRAS-approved material
Assembly	Fully pre-built
Min inlet pressure	0.5 bar recommended
Warranty	5 years

How it compares

Two upright slimline systems in the 450–500L range. The WB-EXT 500 Mini3 is slightly cheaper, has more storage, significantly higher flow, a higher max pressure, WiFi and voice control, variable speed, and named warranties. The Powertank SLIMLINE 450 Fixed offers Fluid Category 4 compliance for those who specifically require it.

Feature	WB-EXT 500 Mini3 this product	Powertank SLIMLINE 450 Fixed
Tank capacity	500L WRAS upright	450L WRAS upright
Pump type	Variable speed (Mini3 — external)	Fixed speed
Flow rate @ 3 bar	50 l/min	40 l/min
Max pressure	5.5 bar	3 bar
WiFi / app	Yes — DConnect, Google, Alexa	No
Noise	45 dB(A)	Not stated
Fluid Category	Cat 1–3 (potable)	Up to Cat 4
Pressure vessel	None (variable speed — not needed)	Yes — 3L integral
Tank warranty	5 years	Contact us
Pump warranty	3 years (DAB)	Contact us
Price (ex VAT)	£770.00	£818.55

Which should I choose?
WB-EXT 500 Mini3 — the better choice for potable water boosting at £770 + VAT. More storage (500L vs 450L), higher flow (50 vs 40 l/min), higher max pressure (5.5 vs 3 bar), WiFi and voice control, variable speed energy efficiency, 45 dB(A) noise rating, named 5yr tank and 3yr pump warranties — and £48.55 cheaper than the Powertank.
Powertank SLIMLINE 450 Fixed — choose only if Fluid Category 4 compliance is a specific requirement for your installation. 450L, 40 l/min, fixed speed, 3L integral pressure vessel. £818.55 + VAT.

Frequently asked questions

How much does it cost and how is it delivered?

£770.00 + VAT (£924.00 inc VAT). Please contact us via WhatsApp or phone for delivery timescales on this product.

What is the difference between the 300L and 500L EXT Mini3 systems?

Both use the same DAB Esybox Mini3 pump with identical performance. The difference is storage and footprint. The WB-EXT 300 Mini3 (£680 + VAT, 600mm × 1200mm) is suited to 3–4 bedroom homes with moderate demand or a reasonable mains fill rate. The 500L (£770 + VAT, 700mm × 1500mm) suits high-demand 3–5 bedroom properties or where mains fill is very slow and maximum overnight buffer storage is important.

Why is the pump external rather than inside the tank?

The “EXT” design mounts the Esybox Mini3 alongside the tank rather than submerged inside it. This keeps the full pump unit completely accessible at all times — for inspection, servicing, or replacement without any need to disturb the tank or its connections. For installations where long-term serviceability is a priority, this is a significant practical advantage over internal pump designs.

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 Mini3 draws from the tank via the 600mm connection hose and boosts pressure throughout the property. A minimum of 0.5 bar incoming pressure is required.

I need 80 l/min — which system should I choose?

For 80 l/min, consider the WB-EXT Slimline 500 Esybox (£1,084 + VAT) — the same 500L EXT format with the full DAB Esybox pump delivering 80 l/min @ 3 bar. For 100 l/min with an internal pump, the WB-INT Slimline 500 Variable Speed (£1,117.75 + VAT) uses the DAB Esybox Diver submerged inside the tank.

What warranties are included?

5 years on the WRAS slimline tank and 3 years DAB warranty on the Esybox Mini3 pump, when purchased from Anglian Pumping Services.

Downloads

DAB Mini3 PDF
Download
Data Sheet PDF
Download

Delivery Information

Standard delivery:

Standard delivery is free for all orders except for some low cost/low margin items where standard delivery is £6.75. Some difficult to transport goods also have a varying carriage charge applied.

Please contact us for the estimated standard delivery times of the products that we have in stock, by dropping us a message on our Whatsapp or Live chat.

Deliveries will typically be made between 7am and 6pm, Monday to Friday (excluding public holidays).

Next day delivery:

Next working day delivery is available for a £15.00 + vat delivery charge.

Orders must be placed before 12 noon to qualify for next working day delivery. Orders placed after 12 noon on Thursday but before noon on Friday will be delivered the following Monday. Orders placed after 12 noon on Friday will be delivered on Tuesday.

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