Dimplex Quantum Direct Unvented Water Heater 300L

£1,739.26 inc vat.
In stock

SKU: QWCD300580

Quick overview

Size:  (HxD) 2065mm x 580mm
Power: 2 x 3000W
Colour:  Black.
Capacity: 300L.
Warranty:  25 years.


The Quantum cylinder is a class-leading and intuitive, smart energy storage water vessel. Offering reliable hot water and low running costs, the Quantum range is available in a choice of five capacities, from 125 litres to 300 litres – all unvented, this is 300 litres model. So there’s a cylinder to suit even the most demanding household.

Provide efficient and economical hot water delivery throughout the home. Working directly from the mains supply of water, they ensure hot water at mains pressure to all outlets in the home. This means fast-filling baths, powerful showers and constant water pressure – even when the washing machine is in use.

They also offer an unprecedented level of control, so that the correct amount of water is stored to accommodate the needs of the household, using the minimum amount of energy. Plus, using a variety of techniques to minimise heat loss has ensured that the Quantum cylinder has unrivalled heat retention capabilities.


Unvented cylinder gives:

  • High flow rates for efficient hot water delivery:
    – Powerful showers and fast-filling baths.
    – Fully compatible with all tap fittings.
  • Light and easy to handle for simple installation.
  • Surface mounted thermostats and sensors for easy installation and maintenance/replacement.
  • Supplied complete with inlet safety group and external expansion vessel.
  • All connections accessible from the front.
  • Slimline models are ideal for smaller spaces.

Environmentally sound performance

  • Pipework routing optimises internal stratification, thereby maximising hot water availability.
  • Side hot water draw off connection, minimises heat losses through the top of the cylinder.
  • 60mm of injected polyurethane foam insulation:
    – Exceeds CHeSS best practice standards for low heat loss and heat recovery.
    – Completely void free, including insulation around immersions and thermostats.
  • Recessed immersion heaters and thermostat housings reduces heat loss.
  • Anti-Legionella: guaranteed self-sterilisation of the cylinder, whilst keeping set temperatures lower during normal operation to help reduce running costs.

Sustainable material

  • Inner vessel manufactured from high-quality Duplex stainless steel:
    – Lightweight, yet ultra high strength and stress/corrosion resistant, ensuring long cylinder life.
    – 100% recyclable.
    – No need for sacrificial anode.
    – 25-year warranty.
  • HIPS/ABS outer cladding:
    – Produced from 100% recycled material.
    – Hard wearing, flexible and damage resistant.
  • CFC/HCFC free injected foam insulation.
  • High proportion of materials (excluding insulation by volume) recycled.


Technical Details:

  •  Unvented Hot Water Cylinder 300 Litre -  18.4kWh at 65DegC Water.
  •  Material: Duplex stainless steel.
  • Outer casing: Black HIPS/ ABS (from recycled materials).
  • Inlet/outlet: Stainless steel.
  •  Insulation: 60mm PU foam (GWP = 1, ODP = 0).
  •  Potable water temperature: 75°C.
  •  Operating pressure: 3 bar.
  • Minimum dynamic pressure: 1.5 bar.
  • Maximum pressure: 12 bar.
  • Minimum flow rate: 15l/min.
  • Cold water inlet: 22 mm stainless steel.
  • Hot water outlet: 22 mm stainless steel.
  • Sensor: Surface mounted.
  • T&P valve: ½" F BSP.
  • Immersion heater: 1¾" F BSP. 
  • 2 x (3kW 240v).
  • Electronic thermostatic control and integrated thermal cut out.
  • Pressure reducing valve and strainer: 3 bar.
  • Expansion relief valve: 6 bar.
  • T&P valve: 7 bar/90°C.
  • Factory pressure tests: 12 bar.
  • Expansion: External.
  • KIWA (water and building regs).
  • Warranty: Inner cylinder: 25 years.
  • Warranty of Immersion heaters: 2 years, excluding the effects of limescale.
  • Warranty of Other components: 2 years.


Delivery time: 10-14 Business Days.

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