We are in the town of Sevenoaks, Kent (UK) where there is a 35 year old floor standing Potterton boiler in the breakfast room, using a flue passing inside a brick chimney.

Old Potterton boiler - casing removed

We specified a Viessmann Compact WB1B 26Kw unit, with a sealed system chimney liner.  This allowed us to install a room-sealed boiler using the stack for exhaust and fresh air inlet.

Getting ready to re-line the chimney

Old boiler flue liner removed

New Viessmann roof terminal being installed, new mortar rendering

We removed the old boiler, rationalised the pipework.  The customer then had the chimney swept, we installed a scaffold tower outside and fitted the Viessmann flue lining and termination kit.

Halfway through the job - old flue hole to be bricked up

Job done, a 30% improvement in boiler efficiency – and the house was unchanged.  Every other ‘gas specialist’ the customer had round said it couldn’t be done.  They should get out more!

Finished - only brown paint required

Green door in Horsham

British Gas condemned the old floorstanding Potterton boiler in the cellar, and they and other contractors suggested that the only solution was the relocation of a new boiler at the other end of the house, involving unsightly pipework throughout.

The existing defunct boiler was flued up a very old chimney weaving through 3 floors; we suggested fitting a new Viessmann Compact 26Kw boiler in the cellar.  The existing system was very old, the cylinder was around 60 years old and the radiators were in their 40s, we estimate.

The system was fully Powerflushed and we converted the gravity system to a fully pumped type, retaining most of the original parts at the customer’s request.

Not a straight or flat wall in sight

The roof of the house was made of stone tiles, possibly York stone, and looked very old and possibly fragile.  Rather than use scaffolding, which would rest on the roof, we suggested a truck mounted access hoist was employed.  We’ve used these in the past and they can offer quick and easy access to some difficult areas without even touching the fabric of the building.

Easy with the right equipment - and a head for heights

The new flue was inserted, and the boiler converted to an ‘open flue’ type, where air is used in the cellar for combustion.

View from the top

Our brief was to keep all the radiators, hot water cylinder etc as before, so some very old pipework remained in the cellar, which we added insulation.

Parking restrictions were everywhere, but Horsham council run a very efficient dispensation scheme for contractors working on these period properties.

Getting the old boiler out of the cellar, this was the easy bit

We left the house with a brand new condensing boiler, but (excluding the cellar) the house looked exactly the same as when we started.

St John the Evangelist, Hildenborough

Our photo shows Dan in contemplation, in the graveyard of St John the Evangelist, in Hildenborough, Kent.  Actually, he’s assisting in a purging operation at the gas meter box.

This church, constructed over 100 years ago, was heated by an old 86kW Ideal Buccaneer commercial boiler.  The boiler had a reputation for breaking down in the hour of need (eg: coldest days of winter) and the management team had found the only way to minimise the chances of failure was to have the boiler on in periods of the summer.

Old Buccaneer boiler

The heating was controlled by a bewildering set of high/low thermostats and timeswitches, and it wasn’t clear to any of the users what, if any, effect they had on the heating.  Large gas bills were being incurred all year round, and the church treasurer concluded that the sooner a solution was found, the earlier savings could begin.

The church management committee wanted a new system, preferably a high efficiency condensing replacement.  The church has a listed exterior, and the boiler plant is in the basement, with a restricted ceiling height.

Interior view of St John the Evangelist

The job was put out to tender;  Hot Water & Central Heating were the only company to propose a modern high efficiency solution.  We suggested a Viessmann Vitocrossal 200 series, which would be a reasonable fit in the congested boiler room, and importantly, it has a very low level flue outlet.  The boiler has an efficiency in excess of 90%, and is exceptionally quiet in operation.

The flue system in a condensing boiler installation requires non corrosive materials, typically stainless steel or plastic in construction.  The system we chose for this job was a Viessmann product, made by Skoberne, and consisted of 150mm diameter plastics sections.  Running the flue outside was not possible due to the aesthetics, so we devised a way of using the old chimney annulus for the majority of the route, with a small break in point in the church to facilitate a swept bend.

This was the only visible works, later boxed in

The old cast iron boiler was broken up and removed.  The opportunity was taken to renew the lighting in the boiler room with 4×55w fluorescent weatherproof battens, which was part of our quotation – as the 60watt bulb was not very effective in a black room.

Part of the old boiler awaiting the scrap contractor

We arranged for scaffolding to be put up around the chimney, as it is over 35feet high, and the installation proceeded apace.

Rick Johnson, our brick maestro subcontractor

The new boiler was installed, together with new pumps and controls.

Vitocrossal 200 stainless steel heat exchanger

We altered the layout of the steel threaded pipework and the gas supply;  the Viessmann Matrix burner and casings were fitted, together with the integrated Vitotrol 100 controls.

Nearly finished!

 Finally, the rooftop work was completed and the scaffolding removed.

Finished chimney termination

The last bit is how the church’s many users will control the heating.  We’ve configured the boiler to work with a standard domestic Honeywell programmable room thermostat.  This will enable the management team to preprogramme temperature levels for the week, keeping the building on a low level heat when unoccupied and at comfortable levels when in use.

Honeywell programmable thermostat

Temperature settings can easily be overriden by church users, but any changes made are temporary – the CM927 we have used will be familiar to many as the easiest to use temperature control currently available.

Many building services engineers fit complex heating controls, but in multi-occupancy buildings there is often no permanently employed person to manage the system, and it is effectively running out of control.  We believe in making things as simple as possible, this is the only way comfort and efficiency can exist together. 

The Viessmann Vitocrossal is a premium product, superbly engineered, and should last many years in this application, whilst reducing energy usage by over 30%.

When finished, the building will incorporate a modern kitchen, and comprehensively remodelled interiors.

We have assisted our customer in the selection of the heating system, but they have also contributed much to the specification, including the innovative Jaga Strada ‘low H20′ high efficiency radiators.

HWCH will be fitting a large underfloor heating grid on the ground floor, a 46Kw Viessmann 200 series light commercial boiler, accumulator boosted DualStream hot and cold water system, all controlled by the Honeywell Hometronic radiator and underfloor control system.

The industrial gas meter has been moved as part of the works, and our commercial gas engineer will be installing a new underground service to the house and swimming pool boilers.

Work is expected to finish in early 2009, but for now,here are some photographs;

Viessmann 46Kw boiler in utility room

Part of the underfloor heating grid just installed

Cylinder cupboard 35mm pipework under test

From the kitchen...........

This customer was having a large extension fitted on the rear of the property, in the form of a wooden Amdega conservatory.

We suggested that water based underfloor heating would be far cheaper to run, and more effective than the electric matting recommended by the conservatory builder.

New Amdega conservatory - underfloor heating by HWCH

The old 50Kw Potterton commercial boiler was removed and replaced with a top quality Viessmann 300 49Kw system boiler with KM bus varispeed pump.

Viessmann 300 49Kw in utility room

The house suffered from inadequate heating in the triple aspect bedroom and lounge, and also the large number of rooms meant that heat was being wasted during the day when some of the family were at school.

Repiping the areas into separately controllable zones was not a practical option, so we fitted the Hometronic radiator/UFH management system.  This allows the customer to set temperatures differently throughout the house in up to 16 separate zones, throughout the day/week.

Radiator fitted with Hometronic valve (a bit blurred!)

The lounge is treated as a separate zone, so if the customer has set the temperature to 20C for the evening, the radiators will come on as frequently as necessary, without affecting the rest of the house. 

Hometronic controller for heating and hot water

The conservatory is now lovely and warm, and the Viessmann boiler is saving lots of gas compared to the old inefficient Potterton unit.

The old floorstanding boiler was removed from the hearth in the kitchen, and a Viessmann 100W Compact heat-only condensing boiler was located some distance away in the garage.

House in Smallfield

A vertical flue was fitted in the garage roof by our professional roofing contractor.

New Viessmann boiler in garage

The Viessmann was supplied and fitted by HWCH with our normal 5 year parts and labour warranty.