WaterBoost WB-Compact 4.5 low mains pressure booster (ACM Series)

Which should I choose?

WB-Compact 4.5 — the highest performing inline mains booster we stock. Best for properties with very low pressure, larger homes, or where maximum performance is the priority. Connects via 1″ BSP.

WB-Compact 3.0 — a strong choice for most domestic properties. Slightly lower real-world output (11 vs 12 l/min at 3 bar) and max pressure (3.0 bar) but costs £105 less and uses ¾” BSP.

Stormboost — the budget option at £245 + VAT. Lower real-world output (10 l/min at 1.9 bar) and no smart features, but comes with a 5-year warranty and integral bypass included as standard.

How much does it cost and how is it delivered?

£460.00 + VAT (£552.00 inc VAT). Standard delivery is free for this product, including next working day when ordered before 12 noon on a working day. In stock and ready to dispatch.

Can this pump connect directly to the mains?

Yes — the WB-Compact 4.5 is WRAS approved for direct inline mains connection. No break tank or storage cistern is required. It fits into the incoming supply pipework and boosts pressure throughout your property from a single point.

Do I have low pressure or low flow — what’s the difference?

Low pressure means your taps feel weak even when only one is running — the WB-Compact 4.5 is designed for this. Low flow means pressure is fine with one outlet but drops when more open — typically caused by a restricted supply pipe. A booster pump alone cannot solve low flow. An accumulator tank is usually the right solution. Contact us if you’re unsure.

What is the difference between this and the WB-Compact 3.0?

The WB-Compact 4.5 boosts up to 4.5 bar and delivers a real-world output of 12 l/min at 3.0 bar — one litre per minute more than the 3.0 at the same pressure. It also connects via 1″ BSP rather than ¾”, which suits properties with larger bore pipework. It costs £105 more than the 3.0. For most standard domestic properties the 3.0 is sufficient, but if you need maximum output or have a larger home, the 4.5 is the better choice.

Will it boost pressure to my whole house?

Yes — installed at the incoming mains it boosts pressure to the entire property. Real-world output of 12 l/min at 3.0 bar, with the variable speed design maintaining stable pressure even when multiple outlets are open simultaneously.

Is it suitable for my combi boiler / electric shower / unvented cylinder?

Yes — the WB-Compact 4.5 is suitable for combination boilers, electric showers, mixer showers, and unvented hot water cylinders, all of which require a minimum incoming pressure to operate correctly.

How does the WiFi and voice control work?

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

What is a full-bore bypass and do I need one?

A full-bore bypass is a parallel pipe that allows water to flow directly from the mains if the pump is being serviced or removed, maintaining uninterrupted supply. It is optional — most domestic installations do not need one — but recommended where any interruption to supply would be problematic.

What warranty is included?

3 years when purchased from Anglian Pumping Services.

Is a wall bracket available?

Yes — the optional WaterBoost ACM wall bracket (£42.00 + VAT) allows clean wall-mounted installation. A connection kit and braided hoses are also available — see the “You may also need” section on this page.