7kW Instantaneous Unvented / Mains Pressure Point-of-Use MPN: 94050211

The Santon PowerPack 7kW (94050211) is a compact, unvented instantaneous electric water heater that delivers hot water on demand, directly from the mains cold water supply. Designed as a true point-of-use heater, the PowerPack is ideal for locations where running a hot water supply from a central system would be impractical, expensive, or wasteful — such as garages, outbuildings, cloakrooms, utility rooms, bedsits, and remote commercial handwashing facilities. With a white moulded ABS casing, a glass-reinforced nylon inner vessel, integrated safety thermostat, and a built-in 2.5 bar pressure relief valve, the PowerPack is a robust and well-proven product that has been a staple of UK plumbing and electrical installation for decades. It operates on a single-phase 240V supply and requires a dedicated 40A circuit.

7kW

Heating Power

240V

Single-Phase Supply

210×160

H×W (mm)

1–7 bar

Operating Pressure

88°C

Safety Cut-Out

40A

Circuit Protection

What Is the Santon PowerPack and How Does It Work?

The PowerPack is an instantaneous (also called "tankless" or "multipoint") water heater — meaning it heats water on demand as it flows through the unit, rather than storing a pre-heated volume in a cylinder. Cold mains water enters the unit through the ½" BSP inlet, flows past a copper-sheathed heating element inside the glass-reinforced nylon inner vessel, and exits as hot water at the ½" BSP outlet. There is no waiting for stored water to reheat, and no heat loss from a standing cylinder — water is hot immediately from the moment flow starts, and heating stops the moment flow stops.

The unit is unvented, meaning it operates at mains pressure and does not require an open-vented cold water header tank. It connects directly to the mains cold water supply and discharges hot water at mains pressure — suitable for both shower and spray tap outlets. One outlet can be supplied at a time: the PowerPack is not designed to supply multiple simultaneous draw-off points.

The 7kW heating element produces a useful temperature rise at normal flow rates. At a moderate flow of around 2.5 litres per minute — typical for a spray tap or economy shower head — the PowerPack will raise the water temperature by approximately 23–28°C above the incoming cold water temperature. With a UK cold supply temperature of around 10–15°C in winter, this delivers an outlet temperature of around 35–43°C, which is comfortable for handwashing. Reducing the flow rate with the integral flow restrictor increases the temperature rise further.

Key Features & Benefits

⚡ 7kW Instantaneous HeatingHeats water on demand as it flows through the unit — no cylinder, no heat-up wait, no stored water to lose heat overnight. Water is delivered hot from the first second of flow, making the PowerPack far more responsive than any stored hot water system.

🚿 Shower & Spray Tap CompatibleCan supply a shower outlet or a spray tap — one at a time. The 7kW output is well matched to economy and low-flow shower heads and spray taps. It is not suitable for high-flow body jets or rainfall heads, which require higher flow rates than the element can heat effectively.

🔧 Compact & DiscreetThe PowerPack's small footprint (210mm H × 160mm W × 104mm D) allows it to be mounted in tight spaces — under sinks, inside vanity units, in airing cupboards, or on any flat wall surface. It can be completely concealed behind a cupboard door or decorative panel, providing a clean, unobtrusive installation.

🏠 Mains Pressure — UnventedConnects directly to the mains cold water supply with no need for a cold water header tank. Delivers hot water at mains pressure for a satisfying flow rate. The supplied 2.5 bar pressure relief valve (PRV) and flow restrictor manage water pressure within the unit's operating range.

🛡️ Integrated Safety ThermostatA pre-set thermal cut-out activates at 88°C to prevent overheating in the event of abnormal operating conditions — for example, if water flow stops unexpectedly during operation. Once tripped, the cut-out requires manual reset by a competent person, preventing the unit from automatically restarting in an unsafe condition.

🏗️ Rugged, Long-Life ConstructionThe outer casing is white moulded ABS — durable, easy to clean, and resistant to impact and moisture. The inner vessel is glass-reinforced nylon — resistant to corrosion and scale buildup in hard water areas. The heating element is copper-sheathed for longevity in a wet environment.

📍 Remote Location SpecialistIdeal for anywhere that is impractical to supply from a central hot water cylinder: a detached garage, a workshop WC, a garden outbuilding, a cloakroom at the end of a long pipe run, or a bedsit with no central water heating. Eliminates the energy and pipe-heat losses associated with long hot water runs.

🔁 Multiple Unit InstallationsWhen higher hot water volume is required than a single unit can provide — for example, to supply multiple remote outlets on a commercial site — several PowerPack units can be installed in parallel on a common cold water manifold. Each unit must receive an acceptable individual flow rate (minimum 2.5 litres/min recommended).

Typical Applications

Garages and outbuildings — provides hot water for handwashing at a remote location without running a hot water supply back to the main dwelling; eliminates the waste and pipe-heat loss of a long pipe run from the boiler
Cloakrooms and downstairs WCs — where the location is remote from the hot water cylinder and a separate point-of-use heater is more practical than extending the DHW circuit
Bedsits and student accommodation — self-contained hot water provision for a single room or unit without dependence on a shared central system
Commercial handwashing stations — staff welfare areas, workshop washrooms, light-industrial facilities where a compact, vandal-resistant heater is needed at the point of use
Concealed installations — the compact unit can be hidden inside a vanity unit, behind a panel, or under a counter, with only the outlet valve and tap visible in the finished space
Rental properties and HMOs — where individual metered point-of-use heating is preferable to a shared central cylinder

What's in the Box

Santon PowerPack 7kW unit — white ABS (94050211)
Integral flow restrictor / outlet valve (fitted)
2.5 bar pressure relief valve with tee-piece (supplied with 7kW model)
Fitting instructions

Not included: Tundish (required for PRV discharge pipe — a 22mm tundish must be connected to drain the PRV safely and is not supplied). Services stop valve. All electrical materials for the dedicated 40A circuit. Installation must be carried out by a suitably qualified person.

Installation Overview

The PowerPack must be installed by a suitably qualified person in accordance with BS 7671 (IEE Wiring Regulations) and Water Supply Regulations. Key requirements:

Electrical supply: 230/240V AC single-phase; dedicated independent circuit with 40A double-pole protection (MCB or fused switch); RCD protection required (may be incorporated in consumer unit); double-pole isolating switch must be within easy reach of the unit — pull-cord or wall-mounted
Earthing: The unit must be earthed; a 10mm² earth bonding conductor must connect to the metal water pipework (cross-bonding)
Water connections: ½" BSP inlet and outlet; incoming water pressure must be between 1 bar minimum and 7 bar maximum; a services stop valve must be fitted on the incoming cold supply
Pressure relief valve: The supplied 2.5 bar PRV must be connected to a safe discharge point via a 22mm tundish to drain — the discharge pipe must not be blocked or capped
Wall mounting: Mount on a flat, even wall surface — do not tile up to the casing. All three fixing holes in the backplate must be used. Allow clearance for the front cover to be removed for servicing
Flow rate: Set the integral flow restrictor during commissioning to achieve the desired outlet temperature — reducing flow increases temperature rise; the 7kW model is supplied with the restrictor set to deliver an appropriate temperature at a moderate flow rate

⚠️ Important — PRV Discharge Pipe Required

The pressure relief valve supplied with the 7kW PowerPack must be connected to a visible, safe discharge point via a 22mm tundish. The tundish and discharge pipework must be installed to Building Regulations Part G requirements. The discharge pipe must terminate in a safe, visible location where hot water discharge will not cause injury or damage — and must never be blanked off or directed to a non-compliant location. Failure to install the PRV discharge correctly is a safety and regulatory non-compliance. The tundish is not supplied and must be ordered separately.

Temperature Rise Performance Guide

Flow Rate (litres/min)	Approx. Temperature Rise at 7kW	Typical Use
1.5 litres/min	~45°C rise	Very low-flow spray tap
2.0 litres/min	~34°C rise	Spray tap / economy wash
2.5 litres/min	~27°C rise	Standard spray tap / low-flow shower
3.0 litres/min	~23°C rise	Moderate shower flow
4.0 litres/min	~17°C rise	High-flow — temperature may be inadequate in winter

Add the temperature rise to your incoming cold water temperature to estimate outlet temperature. Cold supply in winter (UK) is typically 8–12°C; in summer, 15–18°C. Figures are approximate and based on full 7kW output at 240V. Results will vary with supply voltage.

💧 Flow Rate & Temperature — The Key Trade-Off

The PowerPack heats a fixed amount of energy per minute. Reducing the flow rate means each litre of water is heated for longer, increasing the temperature rise. The integral flow restrictor is the primary means of setting the output temperature during commissioning — turn it to reduce flow (increase temperature) or increase flow (reduce temperature). For handwashing with a spray tap, a flow rate of 2–2.5 litres/min will give comfortable warm water temperatures year-round in most UK locations. For shower use in winter, consider whether the 7kW output will deliver adequate temperature at your required flow rate.

Technical Specifications

Specification	Detail
MPN	94050211
Brand	Santon (by Heatrae Sadia)
Model	PowerPack 7kW
Colour	White
Type	Instantaneous (tankless) unvented water heater
Rated power	7kW
Supply voltage	230/240V AC single-phase
Rated current	~29A at 240V
Required circuit protection	40A double-pole MCB or fused isolator
Dimensions	210mm (H) × 160mm (W) × 104mm (D)
Water connections	½" BSP inlet and outlet
Operating pressure (min)	1 bar (0.1 MPa)
Operating pressure (max)	7 bar (0.7 MPa)
PRV setting (supplied)	2.5 bar (supplied with 7kW model)
Safety cut-out temperature	88°C (manual reset thermal cut-out)
Element type	Copper sheathed rod element
Inner vessel material	Glass-reinforced nylon
Outer casing material	White moulded ABS
Outlets	One at a time (shower or spray tap — not simultaneous)
Standards	EN 60335-2-35; BEAB approved; BS/European Standards

Frequently Asked Questions

Can I use the PowerPack 7kW to run a full-pressure mains shower?

It depends on the shower head. The PowerPack works well with economy and low-flow shower heads (typically rated 6–8 litres/min at mains pressure) when used with the flow restrictor to limit the actual flow through the heater to around 2–3 litres/min. Standard full-flow shower heads and any type of body jet or rainfall head require higher flow rates than the 7kW element can heat to a comfortable temperature, so the outlet temperature will be too cool, particularly in winter. The PowerPack is much better suited to spray taps and economy showers than to a full-performance shower outlet. For a dedicated 7.5kW or 8.5kW electric shower, consider a purpose-built electric shower unit instead.

Do I need a plumber and an electrician for installation?

Typically both. The water connections (cold supply, PRV, discharge pipework) should be made by a suitably qualified plumber familiar with Water Supply Regulations and Building Regulations Part G. The electrical supply (dedicated 40A circuit, double-pole isolator, RCD protection, earthing and bonding) must be carried out by a qualified electrician working to BS 7671. In practice, many plumbers hold both water and electrical qualifications for heater work — confirm this with your installer before proceeding.

What is the difference between the 7kW and 9kW PowerPack models?

The 9kW model (a separate product) provides a higher temperature rise at the same flow rate, or the same temperature rise at a higher flow rate — making it better suited to shower applications where higher flow is desired. The 9kW requires a 50A circuit (versus 40A for the 7kW). For handwashing spray taps and cloakroom/garage applications at typical UK flow rates, the 7kW model is usually more than adequate and has a lower electrical infrastructure cost.

Can this be installed in a bathroom or shower room?

Yes, subject to the zone requirements of BS 7671 Part 7 (Section 701). The PowerPack is not IP-rated for installation within Zone 1 (directly above a bath or shower tray). It can be installed in Zone 2 or outside the defined zones in a bathroom, provided the electrical installation meets the relevant zone requirements and appropriate circuit protection is in place. In a shower room or wet room where the unit is not in a defined hazardous zone, installation is straightforward. Always confirm zoning with your electrician.

Does the PowerPack work in hard water areas?

The PowerPack is designed to cope with normal UK mains water supplies including hard water. The glass-reinforced nylon inner vessel and copper-sheathed element are both chosen for their resistance to scale deposition. In very hard water areas (over 300ppm), a limescale inhibitor fitted on the incoming cold supply can help extend service life and reduce the frequency of element descaling. Routine periodic inspection by a competent person is recommended, as with all instantaneous water heaters in hard water areas.

ℹ️ Spare parts for the Santon PowerPack 7kW: Heat Exchanger Assembly 7kW — 95606965 · Temperature Limiter 1 — 95612035 · Temperature Limiter 2 — 95612036 · Pressure Differential Switch Assembly — 95613004 · PowerPack Cover — 95614107 · Neon Assembly — 95615058 · Inlet Boss Assembly — 95607106 · Outlet Boss Assembly — 95607109. Always quote the rating label details when ordering spare parts.

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Heatrae Sadia

Santon PowerPack 7kW Instantaneous Water Heater Unvented Point-of-Use White