From our technical experts

Thermalec Spa Heater 2.5KW – 7.5KW

  • 2 year guarantee
  • Spiral flow design
  • Solid and robust
  • Titanium Elements
SKU: 2727 Categories: ,


Thermalec Spa Heater (Model 12THR) 2.5KW – 7.5KW

Standard Model Heaters 12THR  2.5kW – 12kW  230/400V

Complete with all necessary controls to operate the heater, including contactors, pool temperature controller, manual reset excess temperature stat, and diagnostic lights.  Due to the inherent safety of the patented Thermalec Spiral Flow design these heaters do not have to rely upon a flow switch or pressure switch – nor should one be fitted by the installer.

The construction of the heater is solid and robust, to ensure years of safe and reliable service.
The contact materials are highly resistant to corrosion from pool chemicals. Thermalec® pool and spa heaters can safely be used with sea water pools as well as in demanding applications such as Hydro- and Thalasso- therapy.
The watts density of the heating elements is very low (9.54 W/cm²), ensuring minimal scale build-up and long element life.
The heating elements are always submerged in water. Any air bubbles entering the heater pass through it above the water and across the unheated parts of the elements, preventing any damage to the latter.
The patented weir and baffle system inside the heater causes the water to flow through it in a spiral. This increases uniformity of the water temperature inside the heater and prevents direct impingement of cold water onto the elements.
The spiral flow regime of the water inside the heater discourages scale formation, extending element life.
Thermalec® heaters are flexible: The water flow direction is normally left to right. If required, this can be easily changed on installation by means of a simple modification. Most models may be easily changed by a qualified electrician from single to three phase operation and vice-versa.
The thermostats used in Thermalec® pool and spa heaters have a low operating differential. This is essential to maintain the swimming pool at a virtually constant temperature.
Heaters with higher operating differentials are likely to allow the pool to cool to an uncomfortably low temperature before switching the heating on.
Top quality contactors have been used and their ratings generously selected to give a long service life and minimum risk of operational problems, particularly in pool plant room
As a safety precaution, the heaters are provided with an interlock relay, which has to be connected to the filter pump control circuit. The heater will not operate unless the interlock is wired and the filter pump is energised.
Status indicator lamps on front of panel to facilitate troubleshooting and diagnostics.
Thermalec® pool and spa heaters comply with all current and relevant EU regulations and directives.
Thermalec® pool and spa heaters have a two-year guarantee

Additional information


12THR/2.5 Pool Volume – 7m3, 12THR/3 Pool Volume – 8m3, 12THR/4 Pool Volume – 11m3, 12THR/5 Pool Volume – 14m3, 12THR/6 Pool Volume – 16m3, 12THR/7.5 Pool Volume – 21m3

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Returns Policy

Your rights to return goods are protected under the EU Distance Selling Directive.

You are entitled to cancel your order and return the goods within 7 working days for a full refund not including the cost of delivery. Do this by contacting us by email or telephone and quoting the order number supplied to you. Your refund will be paid within 30 days. You are responsible for the cost and risk of loss or damage when returning the goods, so you should take out enough postal insurance to cover their value. This cancellation policy does not affect your rights when we are at fault - for example, if goods are faulty or incorrectly-described.

Exclusions: Bespoke items (made to measure items) are not included and cannot be returned. If a bespoke item is faulty then the product warranty /guarantee will take effect.

Any goods returned should be in saleable condition.

These terms apply to your order. We may change our terms and conditions at any time, so please do not assume that the same terms will apply in the future.

None of these terms affect your legal rights and these are not diminished in any way. If any term is held to be invalid under any applicable statute or rule of law, that term is automatically omitted from the terms to minimum extent necessary to comply with the law and without affecting the validity or enforceability of the remainder.