Part of the front elevation

We were asked to specify a replacement for the existing Lennox warm air system, using a mixture of radiators and underfloor heating.

Numerous bathrooms in the house and a new annexe were to be converted to mains pressure hot and cold water systems.

We designed a four zone heating system, for maximum energy efficiency.  An unvented hot water system augmented by a TWS water boosting accumulator supplied the bathrooms.  A Worcester 30CDi boiler provided the engine room function.

Part of the garage plant

At the customer’s request, all the plant was to be located in the new garage.

Pipework detail

Worcester Bosch CDi boiler

Underfloor heating in new kitchen/dining areas

Lastly, we have a moody picture of the Vaillant 310 litre unvented and the accumulator.  I take some terrible photos with my iPhone and this is one of them.

Bit dark here

Our customer was very pleased with the installation, which they said performs just like we promised, it was fully completed in January 2011.

Architect designed house in reigate

This property had an old HarcoPak, which is an integrated hot water cylinder and cold water storage tank, mounted in a frame on the 1st floor.

It was heated by an old Potterton Kingfisher 100BF floorstanding boiler, which had been installed with a flue a couple of inches from the rear door and an undersized gas pipe;  both of which were contrary to the gas regs at the time the house was constructed, and still are.

We removed the Potty boiler, leaving a large hole for the on site building team of Mizon Builders to brick up.

Old boiler position

We relocated the new boiler into the garage at the other end of the building.  We suggested a Worcester-Bosch 30CDi conventional.  This is a 102,000BTu boiler based on a Junkers design (a German part of the Bosch Group), a rugged wall hung boiler compatible with UK open vented radiator systems. 

New Worcester 30CDi in the garage

Due to the proximity of the neighbouring property at this point in the building, we proposed a vertical flue solution, and our customer was happy to agree.  We used the services of our professional roofing subcontractor, to make the aperture and weatherseal the flue terminal.  We always use our skilled roofing specialists because the work has to last the lifetime of the roof.

New vertical chimney outlet

Next, the hot and cold water.  We converted the systems to an unvented cylinder, where water is at mains pressure to all outlets.  Wherever possible it is best to site the hot water storage where there is a relatively short pipe run to most points of use, so the original airing cupboard was retained and a new 300 litre cylinder shoehorned in.

In 2011 the UK Government are committed to provide ‘feed in tariffs’ for solar generated hot water.  This means the end of cash grants towards the installation of solar hot water, but heralds the beginning of an annual rebate for new, accredited solar installations (it isn’t retrospective).  In preparation for this, we installed an unvented cylinder that has a solar coil – making the addition of solar panels much simpler at a later date.

Range Tribune HE Solar unvented HW cylinder

The Range Tribune HE Solar is a well made unit from the Kingspan Group, which is very similar to the Worcester-Bosch branded Greenskies unvented unit.   It is reasonably common knowledge that they all come from Kingspan, the ones for Worcester get silver paint. 

On to the underfloor heating.  Our customer had a large conservatory area, and a kitchen and utility into which he rather liked the idea of installing underfloor heating.  The problem he had was the finished floor level; using conventional water underfloor heating the floor level is typically going to rise by around 75mm.  The alternative is an electric blanket – these are cheap to buy, cheap to fit, and around 300% more expensive to run than a gas fired UFH system.  Also, if the small element fails, digging the floor up is the only option.

As the floor already had insulation fitted when the building was constructed around 17 yrs ago, we specified the Velta MiniTEC system.  This unique underfloor system uses a 9.9mm pipe and a special polymer screed system, resulting in a floor uplift of only 15mm.

Velta miniTEC - and a 2p coin for scale

The floor is levelled and then a plastic castellated support sheet is glued to the floor.

MiniTEC being laid

Over a period of a few hours the rest of the support system was laid and the pipework grid overlaid.

Underfloor nearly finished

The existing radiators were prepared by Powerflushing, and separate heating zones set up to enable timed, programmable temperature areas.

Most of the new pipework was conveniently hidden and insulated within voids in the eaves.  A 28mm water supply pipe was installed for the new unvented cylinder supply, to obtain the best performance from the existing water main.

8 days later the works were completed, I look forward to seeing the finished kitchen area!

View from the road

Our customer already has a ‘Hot Water & Central Heating’ installed oil fired cooker range (see our Heritage cooker page above), and was building an outside barn further down the garden.

The central heating boiler was an old oil fired unit, which was located in the hallway and could be heard throughout the property.

Our customer wanted a new boiler and also wished to convert the water system to a new unvented type.

Hot Water & Central Heating suggested that a Grant 3646 outdoor module was fitted, this is an outdoor boiler incorporating a weatherproof housing, designed to operate outside in all weathers. 

Grant Vortex condensing high efficiency outdoor boiler module

This freed up the cupboard in the hall, previously home to an oil boiler and a small vented hot water cylinder on braces above.  We removed these units and replaced them with a Range Tribune Slimline 210 litre unvented cylinder.  This upgraded the hot and cold water to mains pressure at all outlets, and removed the need for a loft mounted storage tank.

Range Tribune unvented installation in cupboard

In common with all unvented systems (and other forms of direct fed hot and cold water systems, like combination boilers and heatstores) the performance is greatly improved with a good water flow rate.  We ran a new 32mm water pipe to the road outside, for minimum hydraulic resistance.   The local water supply company were engaged to provide a new larger connection to the mains.

New water connection being excavated by Sutton & East Surrey Water

The new oak barn was home to a sun room, together with a utility room and shower room.  Hot Water & Central Heating installed underground pipe ducts to the main house to give hot and cold services, and also to feed the new underfloor heating.

New oak barn

Underfloor heating manifolds are quite large units, and it is prudent to site them where inspection and maintenance is easily carried out after the building works are complete.  This ruled out fitting the manifold under the sink or behind washing machines.  Instead, we installed a 7 zone L&K manifold in the ceiling void area above the utility room, hiding the pipework in a stud wall comprising part of the new shower enclosure.

Underfloor installation waiting for screed

The L&K system used nearly 500 metres of pipe, all laid on Building Regs compliant Quinn  insulation board.  The Underfloor Heating was laid in a day, and the concrete screeding completed the day after.  The flooring will be finished in tiling once the screed has properly dried out.

Another view of the underfloor pipework

Heating manifold hidden in ceiling area

Screed laid, all pipework buried. This area will be tiled soon.

Separate zone controls were fitted for the underfloor area, which were linked by armoured cable buried in a duct to the existing house.  Control of the separate heating zones is by Honeywell CM series programmable room thermostats.

Underfloor heating is an invisible but highly effective system*, and uses less energy to heat a space than conventional radiators.  This is because the human body feels warm at lower air temperatures when using underfloor heating. 

The new boiler works at around 92% efficiency, saving fuel but increasing comfort and reliability.  In common with all our Grant boiler installations, our customer received a 3 year on site warranty on the boiler.

*The only type of underfloor heating to be avoided is the electric type, because electricity costs around 12p per Kwh, compared to around 4.5p for gas fired heating and 6p for oil fired (this was written in June 2009). 

Don’t be fooled by sales literature claiming electric heating is 100% efficient and green, these are half truths.  Electrical heating uses energy generated by (usually) coal or gas in the UK.  From the power station to your house meter box, around 55% of the energy in the gas or coal burnt at the power station is lost in generating and transmission losses. 

So before even fitting underfloor heating, electricity is only 45% efficient.   And that generating efficiency partially accounts for the frightening price.  So a sales person could say electric heating is 100% efficient, but it would be a half truth.  If they said it was cheaper than gas or oil fired heating, it would be a lie.  The only electric heating that is efficient in comparison is using a heat pump, but that is addressed elsewhere on this web site.

Period house in Warlingham, Surrey

Our client has a woodworking business and was constructing an imaginative barn type conversion for their property, with lots of oak beams in an unusual semi circular design.

Firstly, we installed a Heritage Cooker in the existing kitchen.  Fitted with brass trim and a Jade Green enamelled finish, it was also specified with body colour hotplate covers.

Heritage Cooker

This particular Heritage Cooker was a gas fired unit, most of the Heritages we fit are oil fired in very rural locations.

In common with all 3 oven Heritage units, the control panel concealed behind the upper left hand door enables the unit to be timed according to the user requirements. 

Showing hidden control panel

From cold, the Heritage is ready for cooking in as little as 25 minutes.  Try telling this to an AGA owner and they start getting very defensive.  Especially in the summer when their cooker is making the kichen intolerably hot and using completely unnecessary amounts of fuel!

An old Potterton boiler and associated hot water cylinder was removed, and a new Vaillant ecoTEC+ 937 hybrid combination boiler was installed in the extension, together with a new water main.

Vaillant 937

We have fitted lots of this model over the past 18 months.  ecoTEC937 uses a buffer store of preheated hot water, to give a performance of around 200 litres of hot in the first 10 minutes, all from a (large) wall hung boiler.  This is a boiler that is a viable alternative for a small unvented cylinder installation for water delivery, if there is only 25 litres per minute coming in the property.

Separate circuits were installed for the underfloor heating system in the extension and the main radiators in the house.

Underfloor heating and radio controls

The underfloor heating manifold (and electrical consumer unit above) will be concealed inside a larder kitchen unit later in the project.

The underfloor heating is fitted with the OJ electronics radio thermostat system, so our customer has 4 zones of independently controllable underfloor heating, plus a separately timed and programmable radiator system, giving 5 addressable zones of heating in the house.

All ready for Christmas 2008, and the floor tiler!

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.

HWCH specified and installed a full ground floor underfloor heating system, Vaillant 624 system boiler and a manifolded upstairs radiator system.  This allowed the radiators to be fed by seamless pipework, making leaks under the beam and block floor almost impossible.

New build property in Purley, Surrey. WC price on application.

Each floor will be independently controlled as well as each separate underfloor zone. 

Hot water will be provided by a Vaillant uniSTOR unvented cylinder.

The property will be completed in late 2008.