Santon PowerPack 7kW Instantaneous Water Heater Unvented Point-of-Use White
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.
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
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.
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Santon PowerPack 7kW Instantaneous Water Heater Unvented Point-of-Use White
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.
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
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.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
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.
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
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.