Firstly, I must apologise the lack of photographs here.  I have a new iPhone and managed to lose a significant amount of installation photos transferring from the old one.  It was all my fault, not Apple’s!

Our customer has a lovely period property near Gatwick, in Sussex.  It has a very cold kitchen and lounge, and was a conventional system with water tanks in the loft and a hot water cylinder on the 1st floor.

The boiler was an old Potterton unit on the ground floor at the rear of the property.

Now, these old properties are usually a bit tight on cupboard and bathroom space, so our customer wanted to lose the water tanks and hot water cylinder, add a utility room and ideally compress all the boiler and hot water functions into a small area.

Enter the Worcester-Bosch Highflow 550 CDi.  This unit is a hybrid combination boiler, and is identical in size to a washing machine.  It has a 42kW heat engine, and an unvented water store inside.  That is the ‘hybrid’ bit, because the hot water heatstore makes this boiler deliver flow rates of hot water that could normally only be obtained from an unvented cylinder.

For the first few hundred litres of water, the blending of the preheated store and the real time efforts of the combi boiler engine deliver close to 25 litres of hot water a minute.  In real use, the unit recharges its’ heat store very quickly so rarely drops below this output.  It is a powerhouse in a small box.

We removed the old water tanks, the old cylinder on the 1st floor, and the ld boiler, and replaced it all with the Bosch unit.  This used the same flue aperture outside so did not affect the listed building requirements.

New boiler does everything for a 4 bed house

Significant modifications were made inside to the heating system, with new Vogel & Noot Vienna Line radiators throughout.  A Smiths Kickspace fan convector was installed in the kitchen, and pipewor was renewed and upsized in key areas to improve circulation through the radiators.

All pipework in the boiler area was removed from wall ducting and relocated on the ceiling to allow for some new wall openings to be created into the adjacent kitchen.

Checking the combustion settings of the new boiler

As part of a Bosch promotion for Gold Accredited Installers, our customer has the benefit of a 7 year parts and labour warranty on the boiler.

We spent 3 days in this loft

Our customer in Purley had a boiler fitted by Hot Water & Central Heating in 2005, and was in the process of having a bathroom refitted. 

Vaillant ecoTEC installed in 2005 - as good as new

Their old gravity water system cylinder was in the way of a new shower enclosure.

Old gravity cylinder - recycling beckons

We worked alongside their bathroom installers (Visions) to swap over from a vented bathroom setup to a new unvented cylinder in the loft. 

Tim holding up the uniSTOR 260

Our customer is a retired chemical engineer, and he specified one of the first Vaillant weather compensated heating systems when we originally installed his Vaillant ecoTEC 630 boiler in 2005.

Naturally, he decided to go for a Vaillant unvented cylinder, in this case the uniSTOR 260.  He now has what Vaillant describe a ‘total system solution’.  This is where the boiler controls know the precise hot water temperature in the cylinder, and modulate the boiler output according to the scale of the task. 

In a Vaillant total system solution there is no separate timer and programmer, all the heating and hot water is controlled from a single wall mounted controller.  We had fitted a Vaillant VRC400 back in 2005, but recently this has been superceded by the new VRC430, and as this was an inexpensive upgrade, our customer chose to have the newer model fitted at the same time.

Latest Vaillant controller was installed

The uniSTOR was sited in the loft space, involving a considerable amount of pipework and subsequent lagging.

There was a surprising amount of pipework in this job

We also upgraded the water supply from the garage, to give the best possible performance at the taps.

New water pipe (insulated) in garage on its way to the loft

Connected to a suitable water supply, unvented hot and cold water systems give a performance level similar to that obtained from a shower pump without the noise and unreliability associated with the latter.

Finished job

They have to be installed by a qualified installer and the safety devices suitably installed;  in our case, we ran the emergency discharge pipe in 28mm copper in a discrete corner of the property, rather than using the nearer back of the house, which would have been unsightly.

Discharge pipe was run at side of house

HWCH were asked to suggest a new gas central heating system design, to replace the existing electrical heating system.

A Vaillant ecoTEC 837 fast flow combination boiler was sited in the loft; as no suitable locations existed, we constructed a frame with a fire resistant lining to support the boiler and accessories.

The boiler flue was passed through the pitched roof, all external works as usual were entrusted to our specialist roofing contractor.

The job included 10 Vogel & Noot radiators, and the new Vaillant VRC430 weather compensation system.

We are great believers in the principle of weather compensation; that is, changing the temperature of the radiators according to external weather conditions to the lowest possible. The simple benefit of such a system is that your boiler is always working in the highest efficiency band possible, so you use the minimum amout of fuel – and give off the least emissions.

A properly installed Weather Compensation system does not lower the room temperatures from optimum, so there is no trade off in comfort terms.

We just wish the manufacturers would make it easier for homeowners to understand!

The new Vaillant VRC430 is a huge improvement on their previous controller (VRC400) in this respect.

As a footnote, we have subsequently received very nice letter from our client – a copy of which is available in our office for inspection!