Sector: Offices
Building: Multi-tenanted office building
Products: Powerstock glass lined calorifier
Application: Domestic Hot Water (DHW) 500l


In this multi-tenanted building in the heart of London, hot water is paramount for hand washing facilities, particularly in the current climate with hygiene being an important factor in reducing the transmission of Covid-19. 

The building had an aged Lochinvar gas fired water heater that had split on the heat exchanger and was therefore condemned. The client needed to get hot water running on site urgently as this unit was their only source of hot water for the building.

Shaun Sylvester, Commercial Manager for UK South Services Ltd, surveyed the site and encountered a number of issues, mainly related to the flues:

“The existing flue had not been installed correctly. It didn’t meet the manufacturer’s recommendations and there was no flue liner in the stack. There was also asbestos present around the entrance to the flue stack and plant room walls.

We looked at the option of using the existing boiler flue header as a combined flue to add a new water heater, but it was too low to accommodate it.”

Keeping costs to a minimum

This was an unexpected failure for the client and therefore an unplanned expenditure. They wanted to keep cost to a minimum as they were not planning on keeping the building for a long period.

 Shaun went on to say:

“The existing boilers were in good order and had more than sufficient KW output to cope with the heating system plus the hot water. Therefore, adding a calorifier that is heated via the boilers to meet the hot water requirements was the best answer to overcome the flue issues and keep costs down for my client.”

UK South Services Ltd opted for a Hamworthy Powerstock PS500 calorifier with unvented kits. A 9kw immersion heater was also fitted to ensure the client has hot water back-up in case of boiler failure. The twin coils in the calorifier provide an extended surface area and therefore large heat transfer for fast heat up and quick recovery.

Hamworthy were able to meet the tight project deadlines and UK South Services Ltd got the building up and running quickly with hot water.