WaterBoost ATX Whole-House Mains Pressure Booster
WaterBoost ATX-450 PURE Whole House Mains Pressure Booster
- Established 1975
- Trusted by thousands of customers
The WaterBoost ATX-450 Pure is the hygiene-specification version of our highest-capacity ATX booster, connecting directly to the incoming cold water mains. It pairs a 450-litre Flow-Thru™ anti-Legionella vessel with a variable speed pump in a single compact unit. A patented scoop and water vane constantly recirculate the stored water — so the water in your home stays as fresh as the day it arrived. No break tank, no overflow, just two water connections required.
Peak burst flow reaches up to 80 l/min, with 36 l/min at 3.2 bar sustained for up to 11 minutes — before settling to a continuous boosted flow of 12 l/min at 3 bar until the vessel recharges. The 450-litre vessel provides 270 litres of useable working capacity. Variable speed inverter technology means the pump only generates the pressure your mains can’t already deliver, at a quiet 40 dB(A). WiFi via the H2D App enables remote monitoring and control. A mains bypass fits in seconds using 2 clips.
Flow-Thru anti-Legionella vessel — total recirculation, no stagnation, the freshest water quality possible. Completely maintenance free. Ideal for discerning homeowners wanting the freshest water, plus landlords, HMOs, care, hospitality and healthcare under a Legionella duty. 5-year tank warranty, 3-year pump warranty. Prefer sealed boosting without recirculation? See the standard ATX-450.
3yr pump
Anti-Legionella
Freshest water
WRAS approved
Zero maintenance
Sealed — no air contact
Flow-Thru recirculation
Variable speed
450L · 270L useable
No overflow
Dry run protection
Bypass fits with 2 clips
More about this product
3yr pump
What is the ATX-450 Pure?
The WaterBoost ATX-450 Pure is the hygiene-specification version of our highest-capacity ATX booster. It connects directly to your incoming cold water mains, combining a 450-litre Flow-Thru™ anti-Legionella 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, and just two water connections required.
Where a standard accumulator stores water on a single dead-end connection — sealed from the air, but static at depth — the Flow-Thru vessel constantly recirculates its full contents. A patented internal scoop and water vane force fresh water through the chamber every time the system runs, so the water in your home stays as fresh as the day it arrived.
The 450-litre vessel provides 270 litres of useable working capacity, sustaining a boosted flow of 36 l/min at 3.2 bar for up to 11 minutes — sufficient for three or more showers running simultaneously — before recharging automatically. Peak burst flow at the moment of demand reaches up to 80 l/min. Once the stored volume is exhausted, the system continues to deliver a boosted 12 l/min at 3 bar until demand ceases. Variable speed inverter technology means the pump only generates the pressure your mains can’t already provide, at a quiet 40 dB(A), with WiFi monitoring via the H2D App.
Energy efficiency — only boosts what your mains can’t deliver
The variable speed pump continuously measures incoming mains pressure and adjusts its output to produce only the shortfall. If your mains delivers 1 bar and your target is 3 bar, the pump generates 2 bar. If your mains delivers 2 bar, the pump generates 1 bar. No wasted energy, no fixed worst-case output.
This is a fundamental advantage over water storage tank boosters, which run at the same full output regardless of what the mains already provides. Running costs with the ATX-450 Pure reflect exactly what is needed — nothing more.
Freshest water — Flow-Thru anti-Legionella recirculation
Stagnation is the enemy of stored water. In a standard sealed accumulator the deepest water in the diaphragm can sit undisturbed for long periods. The patented Flow-Thru design removes that risk: every time water moves through the system, an internal scoop diverts it up into the chamber and a water vane drives total turnover, so fresh water is constantly forced through and microbial colonisation cannot establish.
At the heart of the vessel is the patented CAD-2 controlled-action diaphragm. Its steel clench ring regulates membrane movement and keeps the diaphragm off the tank wall for a long, reliable service life, and the air-valve cap is sealed with closed-cell foam for a leak-free pre-charge. The Flow-Thru series conforms to European and UK recommendations for the elimination of stored-water stagnation.
Incoming system water is diverted up into the tank chamber rather than parking at the inlet.
The patented water vane drives full recirculation of the chamber — no dead volume, no stagnant pockets.
Continuously turned-over water leaves the tank to the property.
Anti-Legionella by design. The Flow-Thru vessel constantly recirculates its full contents, eliminating the static, stagnant volume found in conventional stored-water systems — the freshest water quality possible. WRAS approved for use with potable water.
How it compares — hygiene by design
Every WaterBoost booster is a sealed, pressurised system and already beats open storage on hygiene. The Pure goes one step further with active recirculation — the right choice wherever freshness or demonstrable water turnover matters.
| Hygiene credential | Open break tank | Standard ATX (sealed) | ATX-450 Pure (Flow-Thru) |
|---|---|---|---|
| No open water surface | ✗ Exposed | ✓ Sealed | ✓ Sealed |
| No overflow / hygiene risk point | ✗ Required | ✓ None | ✓ None |
| No static / stagnant stored volume | ✗ Sits static | − Reduced | ✓ Total recirculation |
| Active anti-Legionella turnover | ✗ | − | ✓ By design |
| Constant fresh-water turnover | ✗ | − | ✓ Yes |
| Routine tank cleaning required | ✗ Yes | ✓ No | ✓ No |
The standard ATX remains an excellent sealed system for most homes. The Pure is specified wherever the freshest possible water, or a documented Legionella control regime, is the priority.
Zero maintenance — fit it and forget it
The ATX-450 Pure is a completely maintenance-free system. There are no consumable parts, no filters to replace, no annual service requirements and no engineer visits needed. The sealed, recirculating design removes the hygiene maintenance obligations of open storage and leaves no static volume to manage, while the built-in anti-seize exercise function and dry run protection mean the system manages its own long-term health automatically.
What happens after installation
| Day 1 — Installation | Two water connections. Unit installed and commissioned. That’s it. |
| Year 1 — Nothing | No service visit. No filter change. No tank clean. Flow-Thru keeps the water fresh; system self-monitors via app. |
| Year 2 — Nothing | Anti-seize function runs automatically during low-demand periods. No action required. |
| Years 3 & 4 — Nothing | Pump warranty active. Dry run protection monitoring. Still no maintenance. |
| Year 5 — Warranty | 5-year tank warranty still in force. System continues to operate without scheduled maintenance. |
⚡
30-second pump swap — unique dock system
If a pump replacement is ever needed, the ATX dock system allows the pump unit to be removed and replaced in under 30 seconds using two clips — no draining, no tools, no plumber required. The built-in bypass keeps the property on mains supply throughout.
How it works — two-phase operation
The ATX-450 Pure stores a ready supply of pressurised water in its 450-litre Flow-Thru vessel. When demand occurs, it delivers instant high-flow boosted water immediately, then continues at a sustained flow once the stored volume is used, before recharging automatically — with the stored water continuously recirculated throughout.
Phase 1 — Stored volume
Instant high-flow boost
36 l/min
at 3.2 bar — for up to 11 minutes
Delivered directly from the pre-charged vessel. Peak burst flow reaches up to 80 l/min. Suited to three or more showers running simultaneously or high-demand whole-house use.
Phase 2 — Continuous mains
Sustained boosted flow
12 l/min
at 3 bar — continuous
Once stored volume is exhausted, the system continues boosting from mains. Vessel recharges automatically when demand stops.
Technical specifications
| Brand / Model | WaterBoost — ATX-450 Pure |
| System type | Integrated accumulator booster — direct mains |
| Vessel | Flow-Thru™ anti-Legionella, steel (GFU-450LV) — patented recirculation + CAD-2 diaphragm |
| Water connections | 2 — inlet & outlet · 1¼” BSP outlet (through-flow vessel) |
| Accumulator capacity | 450 litres total · 270 litres useable working capacity |
| Peak burst flow | Up to 80 l/min |
| Sustained boosted flow | 36 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 (vessel rated to 8.6 bar) |
| Pump type | Variable speed inverter |
| Noise level | 40 dB(A) |
| WiFi / connectivity | Yes — H2D App + on-unit HMI display |
| Hygiene | Sealed pressurised circuit + total Flow-Thru recirculation — anti-Legionella by design |
| Vessel dimensions | 1537 mm (H) × 660 mm dia · ~70 kg empty vessel · ~340 kg filled. [Overall height with controller — confirm] |
| Dry run protection | Yes — built in |
| Anti-seize exercise function | Yes — automatic |
| Maintenance bypass | Fitted in under 30 seconds using 2 clips |
| WRAS approved | Yes |
| Maintenance required | None — completely maintenance free |
| Warranty | 5-year tank · 3-year pump |
| Suited to | Discerning homeowners wanting the freshest water · landlords, HMOs, care, hospitality, healthcare, education · 3-4+ bed & high-demand properties |
Flow rates are dependent on incoming mains supply. Continuous flow of 12 l/min applies after stored volume is exhausted.
Frequently asked questions
What makes the Pure different from the standard ATX-450?
It uses the Flow-Thru anti-Legionella vessel in place of the standard accumulator. A patented scoop and water vane force the stored water to recirculate continuously, so it never stagnates — the freshest water quality possible. It also delivers a higher peak burst flow of up to 80 l/min. Useable working capacity is the same 270 litres.
Will the water really stay fresher?
Yes. In a conventional accumulator, water at depth in the diaphragm can sit static. The Flow-Thru design constantly turns over the full contents of the vessel during normal use, so there is no stagnant volume and the stored water is continuously refreshed.
Does it help with Legionella risk assessments?
It supports your control measures — a sealed circuit with no open surface, no overflow, and continuous recirculation rather than static storage. It does not replace a competent Legionella risk assessment, which remains the duty-holder’s responsibility under ACoP L8 / HSG274.
Is the performance the same as the standard ATX-450?
The sustained and continuous figures are identical — 36 l/min at 3.2 bar for up to 11 minutes, then 12 l/min at 3 bar. The peak burst flow is actually higher on the Pure, at up to 80 l/min.
Does it connect to the mains the same way?
It connects directly to the incoming cold water mains with an inlet and an outlet. The key difference is internal: the vessel is plumbed through-flow (water passes in one port and out the other) so the recirculation effect is achieved during normal use.
Is a standard (non-Pure) version available?
Yes — the standard ATX-450 offers the same sealed boosting without active recirculation, at a lower price point. The Pure is for those who want the freshest possible water or a documented hygiene specification.
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Data Sheet PDFDownload
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Manual PDFDownload
Standard delivery:
Standard delivery is free on most orders. Some items may incur a delivery charge depending on weight, size or value. Any applicable charge will be displayed at checkout.
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 £16.50 + 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.
Pallet/Large/Difficult items:
Some large, heavy or difficult to transport items may incur an additional delivery charge. Please contact us for a delivery quote before ordering.
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Frequently Asked Questions
Quick answers to common questions about the WaterBoost ATX-450 PURE Whole House Mains Pressure Booster. For technical specifications, see the product details above; for sizing or installation advice, contact our team. If you have any other questions, we're happy to help.
What is a mains pressure boosting system?
A mains pressure boosting system increases the pressure and flow of water from the incoming mains supply into a property. It typically combines a pump and a storage or expansion tank, drawing water from the mains and delivering it to taps, showers and appliances at a stronger, more consistent pressure. They are used where the incoming mains is too weak to serve modern outlets reliably.
When do I need a mains booster pump?
You normally need a mains booster if static mains pressure is below 1.5 to 2 bar, if showers run weakly when other taps are open, or if combi boilers struggle to deliver hot water. Anglian Pumping recommends checking static pressure at the stop tap before specifying a system, then choosing a model rated for the number of bathrooms and outlets in the property.
What size mains booster do I need for my home?
Sizing depends on the number of bathrooms, the type of fittings and the static mains pressure. As a guide, a 1 to 2 bathroom property with combi boiler or single shower often needs 1.6 to 3 bar boost. A 2 to 3 bathroom property typically needs 3 to 4.5 bar with an integral break tank. Larger homes need a tank-and-pump system such as the DAB Esybox with Esytank or a Powertank set.