Dimplex slimline storage heaters – the XL and XLS ranges

The Dimplex XL and XLS ranges of storage heaters is the UK’s slimmest and most popular storage heaters, offering performance, economy, ultra slim design and maintenance free reliability, having manual & automatic input controls. The XL and XLS series from Dimplex are suitable for a wide range of domestic and commercial applications. The heating level of XL range is adjusted by means of a variable input control, which the occupant sets in line with the changing weather conditions.

The automatic XLS range offers improved comfort, economy and ease of use, with a sophisticated automatic charging system to ensure the level of charge is adjusted to compensate for changing weather conditions without the need for user intervention. At the heart of this system is the patented Twin Sensor®, which meets the requirements of Building Regulations Part L1, which requires all electric storage heaters installed in new build to be fitted with automatic charge controls.

Energy saving features

  • XLS range features automatic charge regulator, which automatically adjusts the level of input charge to compensate for changing weather conditions without user intervention.
  • Running cost savings of up to 15% can be achieved using automatic controller compared to manual static storage heaters.

XL and XLS Storage heaters features

  • Less than 150mm (6″ deep).
  • Smooth curved styling.
  • Dimplex XL range features manually adjustable charge regulator to control the amount of heat stored during the charge period.
  • Room temperature boost control increases heat output when required and may be used automatically or manually.
  • Easy to use controls, out of sight of young children.
  • Frontal grille for efficient heat distribution.
  • Secure wall fixings for safety.
  • Feet may be fitted under carpet or on top of a suitable floor covering.
  • Matches the PLX range of panel heaters.
  • Compatible with all off peak tariffs.
  • Drip proof construction (IPX2 rated).

Technical specifications

Construction Details – Galvanised finish sheet steel base, mounted on steel feet, supporting double skin front and outer panels. One piece front panel/grille assembly and front inner skin remove for brick loading.

Internal Details

  1. Storage Core
    Material: High density bonded magnetite bricks.
  2. Heating Element
    Type: Incoloy sheathed in units of 850W.
  3. Thermal Insulation
    Type (a) Front and Rear Panels – microporous silica.
    Type (b) Top and Ends – resin free mineral wool.
    Type (c) Base – calcium silicate slab.
  4. Supply Connection
    Located at front right hand end of base – accessible by removal of front panel assembly. Hidden cable support straps at rear of heater allow neat supply cable connection from either side of heater.
  5. Assembly
    Remove front panel assembly then front inner skin. Remove internal packing containing elements, position rear layer of bricks, heating elements, and front layer of bricks.


The control knobs are positioned on the sloping rear top panel of the heater, and are therefore out of sight of young children. The knobs incorporate a cross bar and raised pointer for ease of operation.

  1. Charge Controller – Dimplex XL
    Type: Bi-metal, adjustable from zero charge to fully charged condition
  2. Charge Controller – Dimplex XLS
    Type: Hydraulic close differential room temperature sensing thermostat with external sensor.
  3. Thermal Safety Device
    Type: Bi-metal – manual reset.
  4. Damper Control
    Type: Bi-metal strip, selection variable from early to late or zero boost.
Storage Heater Model Dimension A No. of Slots
XL12/XLS12 542 mm 4
XL18/XLS18 770 mm 5
XL24/XLS24 998 mm 6


  1. Case Assembly and Weights
    Containing assembled heater case and heating elements. Packed in single carton.
  2. Storage Bricks
    Supplied, 2 bricks per pack. Approx weight of brick 7.5kg each. (See below for weight of heater with and without bricks).
Storage Heater Model Weight without bricks
No. of bricks
Weight with bricks
XL12/XLS12 20kg 8 76kg
XL18/XLS18 26kg 12 109kg
XL24/XLS24 32kg 16 144kg

IP Rating
Drip-proof IPX2.
Front panel, sides and top panel – Willow White; rear heat shield, wall spacer and grille – contrasting Birch Grey.
Shelf – An attractive shelf is available in 3 lengths.

These details were taken from the specifications Dimplex has on the Storage Heaters. On our website, you can purchase slimline storage heaters from Dimplex, the XL and XLS series, at the Dimplex Heaters section under Heating, Heating and Ventilation.


  1. This is a great article, going into real in-depth detail regarding storage heaters. I particularly like how you’ve covered so many different aspects surrounding storage heaters. These are the main enquiries that someone looking to invest for the first time would find highly useful, and could be the difference between investing and not.

    A very well thought out and well written blog.

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