The Stuart Turner STORMBOOST (Part No. 47708) is a mains water booster pump designed to improve pressure and flow at the point of entry to a property — installed directly in line with the incoming cold water rising main, after the internal stop-tap. It boosts existing mains pressure by up to 2.5 bar and delivers a maximum output flow of 12 litres per minute. The pump switches on and off automatically whenever a tap, shower, or combi boiler draws water above the 0.6 L/min threshold — no manual switching required. Built with a solid brass head and impeller, a reliable induction motor, and supplied with anti-vibration connection hoses, the STORMBOOST is a WRAS-approved, Made in Britain product backed by a 5-year warranty (upon registration). It is ideally suited to single-bathroom properties with a combi boiler where mains pressure is insufficient.
WRAS
Approved + Kiwa Reg 4
5 years
Warranty (on registration)
⚠ Qualified Installation Required — The plumbing installation must be carried out by a qualified person in accordance with the current Water Supply (Water Fittings) Regulations and Building Regulations. A Type EC verifiable double-check valve (not supplied) must be fitted as required by the Water Supply (Water Fittings) Regulations. The electrical installation must comply with current national electrical regulations and be carried out by a qualified person; a 30 mA RCD must be fitted. The pump requires a 5A fused connection unit.
⚡ Suitability — Check Before Ordering
Suitable for: properties with a direct mains cold water supply, a combi-boiler, and one bathroom, where the mains pressure is insufficient.
Not suitable for: properties where the unassisted mains flow rate is less than 0.6 L/min (minimum flow for the pump to activate); properties with gravity-fed systems from a loft tank; properties where the incoming mains pressure exceeds 6 bar (a PRV must be fitted if this is the case). Not for use with warm or hot water.
Features & Benefits
✔ Fully Automatic Operation
The STORMBOOST activates automatically the instant a flow of more than 0.6 L/min is detected — when any tap, shower, or combi boiler opens. It shuts off automatically when flow stops. There is no manual switching, no timing, and no user intervention required. The induction motor has a thermal trip with auto-reset, so the pump recovers automatically from brief overtemperature conditions.
✔ Patented Integral Bypass
When the flow from the rising main exceeds the pump's own output (i.e. the mains pressure recovers and is sufficient on its own), the patented integral bypass valve automatically directs water around the pump and into the system as normal. This means the pump never throttles the mains supply — if the mains is delivering well, flow is simply passed through without the pump adding unnecessary restriction.
✔ Anti-Seize Exercise Function
The STORMBOOST includes an automatic anti-seize exercise cycle — the pump briefly runs at periodic intervals even when there has been no water demand, preventing the impeller from seizing during periods of low usage (for example during a holiday absence). This significantly extends service life compared to pumps without this feature.
✔ Dry Run Protection
Built-in dry run protection detects if the pump is operating without water flow (for example if the mains supply is interrupted) and shuts the pump down to prevent damage to the mechanical seal and impeller. The pump restores normal operation automatically once water flow is re-established.
✔ Solid Brass Head & Impeller
Both the pump head and impeller are manufactured from solid brass — chosen for durability and resistance to the corrosive conditions that can exist in cold mains water systems, particularly in areas with acidic or aggressive water chemistry. The mechanical seal uses EPDM / PTFE / Aluminium Oxide materials for long-term water-tightness.
✔ Quiet Operation + Anti-Vibration Hoses
The induction motor runs quietly by design, and the two included 205mm anti-vibration flexible hoses (G¾F to 15mm push-fit) decouple the pump from the pipework to further reduce structure-borne noise transmission. Anti-vibration mounting feet are also fitted. The unit is rated IPX4 — splash-resistant, suitable for under-sink installation in kitchen cupboards.
✔ WRAS Approved — Mains Connection Compliant
The STORMBOOST holds full WRAS (Water Regulations Advisory Scheme) approval and Kiwa Regulation 4 certification for direct connection to the cold water rising mains supply. This is the approval needed to comply with the Water Supply (Water Fittings) Regulations 1999 when boosting mains water. Products without WRAS approval cannot legally be connected to the rising main.
✔ Made in Britain — 5-Year Warranty
Designed and manufactured by Stuart Turner in the United Kingdom, one of the most established names in domestic water pumping. The STORMBOOST carries a 5-year extended warranty, activated on registration with proof of purchase via the Stuart Turner website. UK technical support and a network of service engineers are available if issues arise.
✔ Compact — Fits Under Kitchen Sink
At 262 mm tall × 148 mm wide × 215 mm long (excluding hoses) and weighing 6.2 kg, the STORMBOOST is compact enough to install within a standard kitchen base unit — the typical installation location after the rising main stop-tap. Floor or plinth mounting is supported. An 80 mm air gap around the unit must be maintained to allow free airflow and motor cooling.
Technical Specifications
| General |
| Manufacturer |
Stuart Turner (Made in Britain) |
| Product Name / Part No. |
STORMBOOST — 47708
|
| Certifications |
WRAS Approved; Kiwa Reg 4 Certified; UKCA / CE |
| Warranty |
5 years upon registration with proof of purchase |
| Performance |
| Pressure Boost |
Up to 2.5 bar above existing mains pressure |
| Maximum Head (closed valve) |
3.2 bar (32 metres) |
| Maximum Flow Rate |
12 litres/minute (dependent on mains supply flow available) |
| Maximum Working Pressure (inlet) |
6.0 bar (600 kPa) — PRV required if exceeded |
| Flow Switch Sensitivity (activation) |
0.6 litres/min (minimum unassisted mains flow required) |
| Min / Max Water Temperature |
4°C minimum / 23°C maximum (cold mains only) |
| Max Ambient Air Temperature |
40°C |
| Construction |
| Pump Type |
Peripheral |
| Pump Head Material |
Brass |
| Impeller Material |
Brass |
| Mechanical Seal |
EPDM / PTFE / Aluminium Oxide |
| Enclosure Protection |
IPX4 (splash-resistant) |
| Mounting Options |
Floor or plinth (anti-vibration feet fitted) |
| Connections |
| Pump Inlet / Outlet |
G ¾" male |
| Anti-Vibration Hoses (supplied) |
G ¾" female to 15mm push-fit, 205mm long (qty 2) |
| Electrical |
| Motor Type |
Induction — continuous duty (S1); thermal trip / auto-reset |
| Power Supply |
165–265 V a.c. / 1 phase / 50–60 Hz |
| Power Consumption (P1) |
340 Watts |
| Full Load Current |
1.5 Amps |
| Required Fuse Rating |
5 Amps |
| Power Cable Length |
1.5 metres |
| Physical |
| Dimensions (H × W × L) |
262 × 148 × 215 mm (excluding hoses) |
| Weight (including fittings) |
6.2 kg |
Installation Requirements Summary
The following requirements must be met for a compliant and warranty-valid installation:
-
Location: Install inline with the cold water rising main, after the internal stop-tap — typically in a kitchen sink base unit
-
Minimum mains flow: At least 0.6 L/min unassisted flow must be available for the pump to activate
-
Maximum inlet pressure: Must not exceed 6.0 bar — fit a pressure reducing valve (PRV) if required
-
Double-check valve: A Type EC verifiable double-check valve (not supplied) must be fitted per Water Supply (Water Fittings) Regulations 1999
-
Bypass pipe: Recommended — allows pump isolation and removal for servicing without interrupting water supply
-
Electrical: 5A fused spur connection unit; 30 mA RCD; must be earthed; carried out by a qualified electrician
-
Air gap: Minimum 80 mm clearance around the pump for ventilation and motor cooling
-
Hose orientation: Anti-vibration hoses must be installed straight, with no more than 30° of bend
-
Warranty registration: Register at stuart-turner.co.uk to activate the 5-year warranty
Frequently Asked Questions
How do I know if the STORMBOOST is suitable for my property?
The STORMBOOST is suited to properties with a direct mains cold water supply (not a gravity-fed system from a loft tank), one bathroom, and a combi-boiler where the mains pressure is too low for a satisfying shower or adequate flow at multiple outlets simultaneously. To check if it will work, your plumber can test the unassisted mains flow at the rising main stop-tap — if it is at least 0.6 L/min, the pump will activate. If your property has very low mains pressure (below 0.7 bar / 7 metres head — the Water companies' minimum), the STORMBOOST may not provide a significant improvement and a more powerful solution or mains pressure complaint to the water company may be more appropriate.
Will it work with my combi boiler?
Yes — the STORMBOOST is specifically recommended for properties with combi boilers. Combi boilers take their cold water feed directly from the mains, so improving mains pressure also improves the cold water inlet pressure to the boiler. This can significantly improve hot water flow rate and shower performance. However, the STORMBOOST only affects cold mains water temperature (max 23°C) — it does not boost hot water stored in a cylinder or a gravity-fed system. Always ensure the boiler manufacturer's maximum inlet pressure specification is not exceeded (most combi boilers accept up to 3.0 bar at the cold inlet).
What is the patented integral bypass, and why does it matter?
Most of the time, mains pressure is adequate (especially at night or during low-demand periods). During these periods, the STORMBOOST's integral bypass valve automatically diverts water around the pump and into the property's pipework without the pump operating — ensuring maximum flow is always available without the pump creating an unnecessary restriction. This is a key differentiator: without a bypass, a pump in line with the rising main can actually restrict supply when it is not running. The patented bypass also protects the pump if the mains flow temporarily exceeds the pump's capacity.
Why is a double-check valve required and what type?
The Water Supply (Water Fittings) Regulations 1999 require that a pump connected to the rising main must be protected by a Type EC verifiable double-check valve fitted on the inlet side. This prevents any backflow from the domestic plumbing system into the mains water supply — a critical public health protection measure. The double-check valve must be of the verifiable type (i.e. it must be possible to test it in situ without removal). This fitting is not supplied with the STORMBOOST and must be purchased separately. Your plumber will be familiar with this requirement.
How do I activate the 5-year warranty?
The 5-year extended warranty must be registered on the Stuart Turner website (stuart-turner.co.uk) with proof of purchase. Without registration, the standard statutory warranty applies. Registration should be completed by the installer or homeowner promptly after installation. Stuart Turner provides UK-based technical support and a network of approved service engineers throughout the country.
