Our client had a delightful detached house in a secluded road in Oxted, Surrey.

The house had been extended into the loft, and had ended up with three luxury bathrooms.  Unfortunately, the hot water storage cylinder was jammed under the stairs and was too small.  And there were three separate shower pumps (each installed by plumbers with every new bathroom).

The shower pumps were noisy, one was a negative head type (so it suffered from running for short periods in the middle of the night), the hot water cylinder could not be sited anywhere else, and the water tanks took up valuable space in the eaves.

The boiler was an old Potterton Kingfisher light commercial 60Kw unit, mounted in an external boiler house.  Our customer wanted to remove the water tanks and cylinder from the house, and relocate everything into the small outside boiler cupboard.

And she wanted the boiler flue of the new unit to go up the existing chimney.

With this set of rather onerous requirements, there were a shortage of heating and plumbing companies with suitable solutons.

The old boiler was from heat calculations, considered to be oversized at 60Kw.  In fact, a 35Kw boiler would deliver a more than adequate heating performance for the property. 

We estimated that the hot/cold water requirement would be circa 40 litres per minute.  We choose the ACV Heatmaster combination boiler unit, because this can deliver this incredible flow rate into a domestic property.

Most unvented cylinders struggle to deliver this kind of performance, and here we have a combined boiler and hot water generator that can cover all the bases in one simple unit.  Truth is, whilst the ACV is billed as a combination boiler, it is really a hybrid solution, being a croos between a heatstore and an unvented cylinder.

It uses the trusted ACV tank-in-tank technology, and can run in full condensing (high efficiency) mode even when producing hot water.  The heatstore runs at 85C and directly heats the house and indirectly heats the hot water, in an enveloped tank.

The ACV was adapted to run ‘open flue’ up the chimney.  Our customer needed some roof repairs so the scaffolding for the twin walled condensing smooth liner was shared between HWCH and their roofing contractor.

Of course, running a mains fed water system to serve three bathrooms requires a good quality water main. 

In common with most houses, our customer’s water main struggled to deliver 22 litres per minute, and we were looking for closer to 50 litres per minute when those three bathrooms were being used.

To improve the peak water flow rate, a GAH accumulator was fitted in the boiler plant room directly behind the ACV Heatmaster. 

It was a tight fit in there, but what a performance punch we packed in!

Instantaneous hot water, fully condensing performance, boosted water flow, three bathroom showers at the same time, and no plant inside the house.  On time, and on budget.