Send message
Ask a question
List of suppliers/where can I buy
Sample request
I have read and agree to the terms and conditions of usage and The Building Centre's Privacy Policy. Your request will be sent and shared to the selected manufacturers you submit a request to.

Find products

Use our product finder to search for products and materials

Subscribe to our newsletter to receive news about events and exhibitions, innovation and materials on the latest building product innovations, case studies and more.
I have read and agree to the terms and conditions of usage and The Building Centre's Privacy Policy.


Oso Delta is the only indirect water heater with "A" rated energy efficiency in capacities up to 300 litres. Delta achieves an "A" rating through minimisation of standing heat losses by using vacuum insulation panels (in an industry first) combined with 4th generation foam insulation. Delta is the most efficent cylinder on the market, and is the first "A" rated water heating product available across a full range of capacities.

Delta sets new standards across the range. In an era where technological improvements typically move an industry forward by a few percent at best, Delta efficiency is over 25% ahead of the nearest rival at the best-sellimng 210 litre size, rising to over 30% for the largest 300 litre capacitt, with these gains directly inputted into SAP. This can only be achieved using our completely new form of insulation.

Compared to many of the most popular cylinders, Delta is around 35% and 50% ahead respectively for these 2 capacities.

Delta will save consumers energy and money - enough to pay for the entire cylinder over its lifetime, and will assist housebuilders to achieve stringent SAP energy requirements.

Delta is the culmination of years of research to produce an "A" rated cylinder for the launch of the European Energy Related Products Directive (ErP) - heralding the introduction of the familiar energy labels to the water heating industry.

Delta is designed to fit in a standard airing cupboard and have the reliability associated with a seperate expanssion vessel system. the cylinder is compatible with all boilers and can be controlled wither via its own thermostat or using a thermistor probe supplied with many modern high efficinecy boilers.

Delta has a large heating coil to give faster heating and is supplied with a back-up immersion heater. Electrical cables are concealed in conduits in the insulation to tidy up the installation and maximise space efficiency.

An expansion vessel and complete set of inlet control valves are supplied as part of the package. Delta is supplied with a digital thermostat which displays the water temperature and offers holiday and anti-legionella modes.





Find products