WaterBoost Accumulator Vessels
WaterBoost 250 Litre Horizontal Accumulator Vessel AWBH-250LH
In stock
- Established 1975
- Trusted by thousands of customers
The WaterBoost AWBH-250LH is a 250-litre WRAS-approved horizontal accumulator vessel for mains-connected water systems. The horizontal orientation makes it ideal where headroom is limited — fitting neatly in a loft, cupboard, or plant room on its side. Accumulators store mains water under pressure so you draw instantly at full mains pressure the moment you open a tap or shower, delivering noticeably stronger, more consistent flow even during peak demand periods.
The AWBH-250LH operates on a 60% usable volume ratio — delivering approximately 150 litres of high-pressure water before returning to normal mains flow. At a typical shower flow of 12 l/min, 150L supports two simultaneous showers for approximately 6 minutes before returning to normal mains flow. Diaphragm design, WRAS-approved construction, maintenance free. The AWBH-250LH is suited to 2–3 bedroom homes.
Requires a minimum 2 bar static mains pressure to operate effectively. If your static pressure is below 2 bar, add the WaterBoost ACF1 accumulator booster pump to charge the vessel to the required working pressure.

Horizontal — low headroom
Maintenance free
2–3 bedroom homes
ACF1 pump if <2 bar
More about this product
The WaterBoost AWBH-250LH is a 250-litre WRAS-approved horizontal accumulator vessel for mains-connected cold water systems. The horizontal orientation means it installs on its side — ideal for lofts, low-ceiling cupboards, and plant rooms where a vertical vessel would not fit. It stores mains water under pressure so that when you open a tap or shower, water discharges immediately at full mains pressure rather than waiting for the street main to respond.
The vessel operates on a 60% usable volume ratio, delivering 150 litres of high-pressure water per charge before recharging automatically from the mains. Diaphragm design, WRAS-approved construction, maintenance free and completely silent — no pump, no electronics, no servicing required once installed.
Requires a minimum 2 bar static mains pressure. If your pressure is below 2 bar, add the WaterBoost ACF1 boost pump to charge the vessel to the required working pressure.
Recommended vessel sizes for the AWBH horizontal range, based on property type.
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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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