WaterBoost Accumulator Vessels
Water pressure and flow aren’t constant. Peak morning and evening demand on the mains network — plus the long pipe run from the road to your taps — can leave flow weak just when you need it. A WaterBoost accumulator solves this by storing mains water under static pressure and releasing it instantly at point of use, for a strong, steady flow even at the busiest times.
Properties on a shared supply are especially prone to low pressure and flow at peak times. With no pump and no moving parts, the accumulator is silent, maintenance-free and uses no energy — available in vertical and horizontal forms from 150 to 450 litres.
How an accumulator helps
Think of a tennis ball leaving the racket: the further it travels, the more it slows as air resistance saps its power. Your water is the ball and the pipework is the air — the longer the run from the mains to your tap, the weaker the flow arrives. An accumulator stores the water’s energy right at the point of use, so every time you open a tap you get the full “power off the racket” rather than what’s left after a long journey through the pipes.
As demand on the mains rises at peak times, the accumulator discharges its stored volume first — delivering immediate, full-pressure flow — then quietly refills under mains pressure when demand drops. No pump, no electricity, no noise.
Why choose WaterBoost accumulators?
Which size do I need?
Accumulators are sized on roughly 60% usable capacity — a 300 L vessel delivers around 180 L of boosted water per cycle. As a guide, a 2–3 bedroom home suits ~300 L; 4–5 bedroom homes or multiple bathrooms need 450 L or more.
| Model | Capacity | Usable (~60%) | Orientation |
|---|---|---|---|
| AWBH-150LH | 150 L | ~90 L | Horizontal |
| AWB-200LV | 200 L | ~120 L | Vertical |
| AWBH-200LH | 200 L | ~120 L | Horizontal |
| AWB-250LV | 250 L | ~150 L | Vertical |
| AWBH-250LH | 250 L | ~150 L | Horizontal |
| AWB-300LV | 300 L | ~180 L | Vertical |
| AWBH-300LH | 300 L | ~180 L | Horizontal |
| AWB-450LV | 450 L | ~270 L | Vertical |
Vertical (LV) models save floor space; horizontal (LH) models suit lofts and low-headroom roof spaces. Usable figures are approximate and depend on charge pressure and mains pressure.
Low static pressure? An accumulator boosts flow, not pressure. If your static (resting) mains pressure is below 2 bar, pair it with a booster pump to lift pressure to 3–4 bar for the best results.
For stronger, more consistent flow at peak times — with no pump, no power and no maintenance — a WaterBoost accumulator is the simple answer. Choose your size and orientation below.
8 products
The WaterBoost AWB-200LV is a 200-litre WRAS-approved vertical accumulator vessel for mains-connected water systems. Accumulators store mains water under pressure — so when you open…
The WaterBoost AWB-250LV is a 250-litre WRAS-approved vertical accumulator vessel for mains-connected water systems. Accumulators store mains water under pressure — so when you open…
The WaterBoost AWB-300LV is a 300-litre WRAS-approved vertical accumulator vessel for mains-connected water systems. Accumulators store mains water under pressure — so when you open…
The WaterBoost AWB-450LV is a 450-litre WRAS-approved vertical accumulator vessel for mains-connected water systems. Accumulators store mains water under pressure — so when you open…
The WaterBoost AWBH-150LH is a 150-litre WRAS-approved horizontal accumulator vessel for mains-connected water systems. The horizontal orientation makes it ideal where headroom is limited —…
The WaterBoost AWBH-200LH is a 200-litre WRAS-approved horizontal accumulator vessel for mains-connected water systems. The horizontal orientation makes it ideal where headroom is limited —…
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 —…
The WaterBoost AWBH-300LH is a 300-litre WRAS-approved horizontal accumulator vessel for mains-connected water systems. The horizontal orientation makes it ideal where headroom is limited —…
Frequently Asked Questions
Quick answers to common questions about the WaterBoost Accumulator Vessels. 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.
What is an accumulator tank?
An accumulator tank is a pressurised vessel that connects directly to the mains supply and stores water under pressure. When a tap or shower opens, water discharges immediately from the vessel at full mains pressure rather than drawing only from the street main. This delivers stronger, more consistent flow at peak times. Accumulators have no pump and no moving parts so they are maintenance free and silent.
When should I use an accumulator instead of a pump?
An accumulator is the right solution when static mains pressure is adequate – above 2 bar – but flow is poor or drops during peak demand. It boosts available flow without adding a pump, energy use or noise. If static pressure is below 2 bar, a booster pump is needed instead, or an accumulator combined with a charge pump such as the WaterBoost ACF1.
What size accumulator do I need?
Accumulators are typically sized on a 60 per cent usable rule – a 300 litre vessel delivers around 180 litres of boosted water per cycle. As a guide, a 2 to 3 bedroom home suits a 300 litre vessel such as the GWS GCB-300LV. Larger 4 to 5 bedroom homes or properties with multiple bathrooms typically need 450 to 600 litres. Vertical models save floor space, horizontal models suit lofts and roof spaces.