Update 09/06/20 – Sold May 2020

We are selling a second hand Calorex Delta 4 all in one ducted pool unit on behalf of its owner.

Model number: Delta 4


The Calorex Delta units are all in one ducted systems for larger domestic or small commercial indoor swimming pools

This unit provides  pool water heating, dehumidification, air heating and heat recovery from the dehumidification process back to the pool water.


The unit requires ducting into the pool hall, which is not included.

This model is in good working condition but has now been decommissioned

This is a single phase (230v) model with a maximum current of 20.3A and needing a 33A breaker

It provides:-

  • Humidity control
  • Heat recovery
  • Room Air heating
  • Pool Water heating
  • Fresh air ventilation
  • Room Air cooling

The internal measurements of the pool this unit is currently servicing are 11.5 metres (long) x 4 metres (wide) x and average of 1.2 metres (deep) [shallow 900cm x deep end 1500cm) + a roman end.

Total volume is 55.2 cubic metres without the roman end.

The Calorex Delta 4 is really a ‘sledge hammer to crack a walnut’ as it is capable of running a large leisure pool complex.



It is being sold due the pool being removed by the owner

Please contact us if you would like advice on if this unit will be suitable for your pool

It was installed new in 2003 and so is approx 15 years old.

The pool and equipment is serviced every two weeks and last checked over, serviced and replaced some linked parts in January 2019.

The unit does not meet current building regulations and so is suitable for existing pools but not for new-build pools

It is in good condition and will be carefully decommissioned and removed from the pool ready for collection or transit.

These units are approx £20,000 new (inc VAT)

We are selling this unit for £2,500 ono (no VAT)

So save £££££s on the new price, so grab a bargain !!

All reasonable offers will be considered by the seller.

The unit is located in Norfolk at postcode PE31 6QP

Inspection before purchase is welcome.

The buyer can collect, or we can arrange delivery for an additional cost – please ask for a quotation.

Typical Installation

The unit can be collected or delivered to a UK address. Please contact us for a shipping quote if required.

See below for the brochure and user manual

It has full digital controls and a built in time-clock

Product Literature

Heat Siphon 2.25 Model BrochureCalorex Delta 4 Brochure

If you have any questions, please call us on 01268-206560

or email

For more new and second hand heat pumps, see our web site at


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The prices shown include FREE UK delivery for orders over £50 or £6.50 for orders under £50

We can ship to any country. Please contact us for a shipping quote.

The lead time on most items is normally on a 1-2 day delivery,  subject to availability. Please call to check availability.