WaterBoost ATX-300 Accumulator Booster System

WaterBoost ATX-300 Accumulator Booster System - Image 3

WaterBoost ATX-300 Accumulator Booster System - Image 4

WaterBoost ATX-300 Accumulator Booster System - Image 5

WaterBoost ATX-300 Accumulator Booster System - Image 6

WaterBoost ATX-300 Accumulator Booster System - Image 7

WaterBoost ATX-300 Accumulator Booster System - Image 8

Established 1975
Trusted by thousands of customers

The WaterBoost ATX-300 is the largest model in the ATX integrated accumulator booster range, connecting directly to the incoming cold water mains. It combines a 300-litre sealed accumulator vessel with a variable speed pump in a single compact unit — automatically boosting both pressure and flow throughout the property the moment a tap or shower is opened. No break tank, no overflow arrangement, just two water connections required.

The system delivers a peak burst flow of up to 45 l/min and up to 27 l/min at 3.2 bar for up to 11 minutes — sufficient for two or more showers running simultaneously — before settling to a continuous boosted flow of 12 l/min at 3 bar until the vessel recharges. Variable speed inverter technology maintains smooth, stable pressure at a measured 40 dB(A). WiFi via the DConnect app enables remote monitoring and control. Includes dry run protection, anti-seize exercise function, and WRAS-approved pump body materials. A mains bypass can be installed in seconds using 2 clips if the unit ever requires maintenance.

WRAS approved product. Sealed system design — no air contamination. Suited to 2–3+ bathroom properties. 5-year tank warranty, 3-year pump warranty. Step down to the ATX-250 or ATX-200 for smaller properties.

45l/min

Peak flow

3.2bar

Max pressure

40dB(A)

Noise

5yr tank
3yr pump

Warranty

WiFi · DConnect app
WRAS approved
Variable speed
300L — no overflow
Dry run protection
Anti-seize function
Bypass fits with 2 clips

Full Description

More about this product

Full Description

What is the ATX-300?

The WaterBoost ATX-300 is the largest model in the ATX integrated accumulator booster range. It connects directly to your incoming cold water mains supply, combining a 300-litre sealed accumulator vessel with a variable speed pump in a single compact unit — automatically boosting both pressure and flow throughout the property the moment a tap or shower is opened, with no break tank, no overflow arrangement, and just two water connections required.

The 300-litre vessel enables the ATX-300 to sustain a boosted flow of 27 l/min at 3.2 bar for up to 11 minutes — sufficient for two or more showers running simultaneously — before the vessel recharges. Peak burst flow at the moment of demand is up to 45 l/min. Once the stored volume is exhausted, the system continues to deliver a boosted 12 l/min at 3 bar continuously until demand ceases and the vessel refills automatically.

The sealed design eliminates the need for a traditional overflow, and the variable speed pump keeps noise to a measured 40 dB(A). WiFi via the DConnect app enables remote monitoring and control. Dry run protection and an anti-seize exercise function are built in, and the pump body uses WRAS-approved materials throughout. If the unit ever requires maintenance, a mains bypass can be installed in seconds using just 2 clips.

45^l/m

Peak burst flow

3.2^bar

Max pressure

40^dB

Noise at 1m

300^L

Accumulator

WRAS approved · 5yr tank · 3yr pump

How it works

1 — Vessel pre-charges from mains

On installation and after each use, the variable speed pump charges the 300-litre accumulator vessel to the set working pressure, storing a ready supply of pressurised water.

2 — Demand triggers instant delivery

The moment a tap or shower opens, the system activates automatically — delivering an immediate burst of up to 45 l/min, then sustaining 27 l/min at 3.2 bar for up to 11 minutes.

3 — Continuous flow & recharge

After the stored volume is exhausted, the system continues to deliver a boosted 12 l/min at 3 bar directly from the mains. When demand ends, the vessel recharges automatically ready for the next use.

Two-phase operation. Phase 1 — stored volume: up to 27 l/min at 3.2 bar for up to 11 minutes (sufficient for two or more showers running simultaneously). Phase 2 — continuous mains: 12 l/min at 3 bar until demand ceases. Actual flow rates are dependent on the incoming mains supply available.

Key features

Variable speed pump

Inverter-driven variable speed motor adjusts output to match demand — delivering smooth, stable pressure without the surging of a fixed-speed pump, with significantly lower energy consumption.

40 dB(A) — whisper quiet

Water-cooled motor design keeps noise to a measured 40 dB(A) — quieter than a normal conversation and well suited to kitchen larder or utility room installation.

WRAS approved — pump body materials

The pump body is constructed from WRAS-approved materials, ensuring safe contact with potable water throughout. The complete system carries WRAS product approval.

Dry run protection

Built-in dry run protection prevents pump damage if the system runs without water — an important safeguard during initial installation or in the event of a mains interruption.

Anti-seize exercise function

An automatic anti-seize exercise function periodically runs the pump during periods of low demand — preventing the impeller from seizing during prolonged inactivity.

Mains bypass in seconds

If the unit ever requires maintenance, a mains bypass can be fitted in seconds using just 2 clips — keeping the property on a direct mains supply throughout the service period.

The ATX-300 also features a sealed system design requiring no overflow arrangement, just 2 water connections for installation, and built-in WiFi to the DConnect app for remote monitoring and control.

Technical specifications

Brand / Model	WaterBoost — ATX-300
System type	Integrated accumulator booster system
Connection	Direct mains (2 water connections)
Accumulator capacity	300 litres
Peak burst flow	Up to 45 l/min
Boosted flow (stored volume)	Up to 27 l/min at 3.2 bar for up to 11 minutes
Continuous flow (post-discharge)	12 l/min at 3 bar
Max pressure	3.2 bar
Pump type	Variable speed (inverter controlled)
Noise level	40 dB(A)
Pump body	WRAS-approved materials
Dry run protection	Yes
Anti-seize exercise function	Yes
WiFi / connectivity	Yes — DConnect app
Overflow required	No — sealed unit
Maintenance bypass	Fitted in seconds using 2 clips
WRAS approved	Yes — WRAS approved product
Warranty	5-year tank · 3-year pump
Suited to	2–3+ bathroom properties · combi-boiler homes

How it compares

Feature	WaterBoost ATX-300	Stuart Turner Stormboost 300
Tank capacity	300 litres	300 litres
Connection type	Direct mains	Direct mains
Peak burst flow	Up to 45 l/min	Not stated
Boosted flow (sustained)	27 l/min for up to 11 min	27 l/min for up to 11 min
Continuous flow (post-discharge)	12 l/min at 3 bar	12 l/min
Max pressure	3.2 bar	3.2 bar
Pump type	Variable speed	Fixed speed (induction motor)
Noise	40 dB(A)	Quiet (no dB rating stated)
WiFi / app control	Yes — DConnect app	No
Overflow required	No — sealed unit	Standard arrangement
Maintenance bypass	2-clip fit — seconds	Integral bypass
Water connections	2 connections	Anti-vibration hoses included
Dry run protection	Yes	Yes
Anti-seize exercise function	Yes	Yes
Pump body	WRAS-approved materials	Brass body & impeller
WRAS approved	Yes	Yes
Warranty	5yr tank · 3yr pump	3 years

Flow rates are dependent on incoming mains supply. Continuous flow of 12 l/min applies after the stored volume has been exhausted and the system returns to mains-only supply.

Frequently asked questions

What is the difference between the ATX-300 and the ATX-250?

The ATX-300 has a 300-litre accumulator vessel compared to the ATX-250’s 250 litres, and delivers a higher sustained boosted flow of 27 l/min compared to 24.5 l/min. It is the largest model in the ATX range and is best suited to homes with two or more bathrooms in regular simultaneous use, or properties with higher whole-house demand. All other specifications — peak burst flow, max pressure, noise level, pump type, WiFi, and warranty — are identical across the ATX range.

How does the ATX-300 compare to the Stuart Turner Stormboost 300?

Both are 300-litre direct mains systems with the same sustained boosted flow of 27 l/min at 3.2 bar. The ATX-300’s advantages are its variable speed pump (vs fixed speed induction motor), measured 40 dB(A) noise rating, WiFi via the DConnect app, sealed system requiring no overflow, and a 5-year tank warranty (vs 3-year total). The Stormboost 300 specifies a brass pump body and impeller, and includes anti-vibration connection hoses. Both carry WRAS approval and include dry run protection and anti-seize function. See the comparison table above for a full side-by-side breakdown.

What happens after the 11 minutes of boosted flow?

Once the stored volume in the accumulator has been used, the system continues to supply water directly from the mains at a boosted 12 l/min at 3 bar. When demand stops, the accumulator recharges automatically. Actual flow rates depend on the incoming mains supply available.

How does the maintenance bypass work?

If the unit needs to be taken offline for servicing, a mains bypass can be installed in seconds using just 2 clips. This diverts the supply directly from the mains, keeping the property on running water throughout the maintenance period. No tools or specialist knowledge required.

Is the ATX-300 suitable for a combi-boiler property?

Yes. The ATX-300 is designed for direct mains connection and is well suited to combi-boiler homes, boosting both hot and cold flow throughout the property. Installation should comply with Water Regulations and be carried out by a qualified plumber.

Is a smaller version available?

Yes. The ATX range also includes the ATX-250 (250 litres) and ATX-200 (200 litres) for smaller properties or lower demand. If you are unsure which size is right, contact us and we will advise.

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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