Our customer in Warlingham, Surrey, UK was having a substantial extension to the side and rear of the property.

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.

Here we are near Tunbridge Wells.

Near Tunbridge Wells UK

Our customer had an old wall mounted Boulter Camray oil boiler on the rear of his house.  The unit was beyond redemption, having had a small internal fire.

Old boiler bites the dust

He quite fancied moving the boiler further away from the house, so we looked into moving it down the garden.  Our customer was a builder, so he created a neat pipe trench and raised boiler plinth to our specifications.  The property has a river running nearby, which has been known to flood, so the raised platform will protect his investment!

Our pipe trench

We suggested a Worcester-Bosch Camray external condensing high efficiency oil boiler would do the trick.

Worcester-Bosch Camray external

The new boiler was connected to the house using barrier plastic pipe, which has low flow resistance and good resistance to frost.  It was insulated with Armaflex external grade insulation.  External armoured cable was laid in the duct and an RCD fitted to enable safer maintenance and accordance with BS 7671.

In common with all our Worcester-Bosch oil installations, the boiler is covered for 5 years on a full parts and labour basis by the manufacturer.

We’d like to extend our thanks to our customer, Ernie, who made a fantastic job of all the preparatory building work, in between replacing his lounge floor!  Our team was awarded with some rather nice wine at the end, too!

Near the Ashdown Forest, in Sussex, UK, is the village of Hartfield.  Apart from being the home of Pooh Bear and featuring what might be the only Pooh Bear shop (!) it is the location for our work this week.

Hartfield location

This was interesting job, our client had an electric boiler which she had, over the last 3 years, invited nearly every heating and electrical contractor within a 30 miles radius to repair.

Pilot Electric boiler and heatstore

The house was of reasonably modern construction, with water underfloor heating.  Coupled to this was a ‘Pilot’ Electric Boiler, and a Thermal store.

Unfortunately, the Pilot boiler had long since been out of production and there were some relay parts needed that were no longer available without altering the circuit board.  This, and a seized pump and two seized valve actuators made us suggest that it was time for whole new heater.

The Pilot Boiler has an interesting history.  Our client was married to the joint inventor, who had unfortunately passed away many years earlier.  He and a business partner had designed a boiler that would heat a large (approx 400 litre) insulated tank of water using electricity bought at the Economy 7 off-peak tariff.  The underfloor heating screed would be warmed up using off-peak electricity, at the same time the heatstore would be warmed up, working like a rechargeable battery, only using energy in the form of stored heat.

The idea was that during the day, the Pilot Boiler would use the stored heat from the heatstore into the underfloor heating first, before requiring energy bought at peak rate.  This meant that the heating energy was being bought at around 3.5p per Kwh (2011 prices) instead of 13p per kwh (2011).  NB:  Gas prices in 2011 are over 4p per kWh.  So it was a clever idea, and in the 80s it was sold with joint marketing of the regional electricity board.  I don’t know how many of these Pilot Boiler setups there are out there, this is the first one I have seen.  Other heat store electric boilers were available  but were not as easy to install or integrated as the Pilot.

As the house already had underfloor heating, and was well insulated, we recommended that an air source heat pump was installed.  We are agents for the Mitsubishi Ecodan system.  There are lots of air source heatpumps out there, but we have found the Mitsubishi people to be reliable, trustworthy, and they take a real pride in their products.  We have been really impressed by their ethics, you can’t install their products unless you have been on their courses, provided proof of insurance etc.

Some recent Goverment funded research has suggested that heatpumps have been mis-sold in up to 80% of installations in the UK, which is not surprising, because lots of companies have sprung up using words like ‘Green’, ‘Sustainable’, ‘Renewable’ etc which are really just sales organisations, rather than heating engineers.

The Mitsubishi system comprises of a small external unit, and an internal pumpstation.  Air Source Heat Pumps work by capturing latent heat in huge volumes of external air.  This is captured in a matrix containing refrigerant and using a ‘vapour compression cycle’ the external low level heat in the air is converted into usable heat at up to around 45C.

Ecodan external unit

The above picture shows the external unit, mounted on noise reducing mounts.  When running, it is quieter than a quality dishwasher.

Air Source Heat Pumps use electricity, and electricity is expensive at around 13p per kWh;  this is where the Coefficient of Performance (CoP) comes in.  For most of the heating season, CoPs of between 300% – 400% should be possible.  In other words, if your heatpump uses 2kW of electricity, it should deliver over 6kW of heat into the house.  This sounds like magic, but the extra energy is the latent heat in the air being extracted.

This particular unit will continue working in external temperatures down to -20C.  The efficiency is not very good when it is -10C outside, but starts looking very good from around 5C upwards.

This all sounds too good to be true….. but it is true, but there are some things you need to be wary of.  For every 10 enquiries we get about these units, only one is viable.  The first thing to know is that this technology is only efficient for heating that needs up to 45C touch temperature.  So if you live in a house with radiators, these will have been sized expecting 75C water to be inside.  45C going through them will not be warm enough.  You can significantly upsize your rads, but then we are going to ask you difficult questions about what the insulation is like in your floors, walls and ceilings.

By far the best partner for heat pumps is water underfloor heating.  The two technologies were made for each other, because UFH wants around 45C.

Back to the install;  we took out the Pilot Boiler and heatstore, wired in the Misubishi internal controller (called FTC2), and linked the output of the external Ecodan to the existing underfloor heating.

New internal installation

For simplicity, we used a standard Honeywell CM907 room thermostat to control the underfloor heating;  our customer need know nothing about the Mitsubishi system because once commissioned, there are no Japanese user controls.  All the interfaces are standard, familiar UK central heating controls, the clever people at Mitsubishi made it this way!

Well, does it work?  We put this system in in early December 2010, and our customer reports that it has performed faultlessly through one of the coldest winters in recent times.

Heat Pumps do work, but they aren’t the answer to everything.  Be very wary of the sales pitch.  However, in this scenario above, it will be cheaper to run than a gas or oil fired system and require less maintenance.  Depending on how the electricity is generated, Co2 emissons will be lower too.

Finally, what is the difference between air source and ground source heatpumps?  The ground source type extract heat from the soil, boreholes or watercouses instead of air, and are usually a bit more efficient.  However, you have to dig holes, there are large quantities of pipework buried underground, and the gear costs more.  Since air source and invertor driven compressors have become more commonplace, the ground source stuff sales have plummeted……

Our client lives in our base town of Edenbridge, Kent, UK.

Edenbridge house

Neat kitchen integration

Our client has demolished his old kitchen in a Victorian house, lowered the floor by 3 feet, removed three walls and a utility room and WC, and is in the process of building a new ultra modern kitchen.

This is an interim post, which will be updated to show the finished job in due course.

We have just removed the old Glowworm boiler from the utility room, and fitted a new Worcester-Bosch 40CDi conventional in the cellar.

This Saturday, we completed the first phase of the underfloor heating, ready for the building contractor to lay the screed on Monday.  We’ve used the Nu-Heat system, and it will comprise 3 zones, each of which will have timed programmable control.  The floor will be a mixture of solid screeded (shown here) and suspended flooring.  The floor finish will be a green slate from a quarry in the Lake District, specially produced for the job and not available in the shops!

This is one of two underfloor installations we have underway this week, we will post more details over the next few weeks.

The old Potterton Netaheat had failed and had been sited in a very rough fashion halfway down some cellar steps.

Old boiler location was to the right hand side of the cellar steps

The hot water cylinder was located above the cellar on a raised floor, which would have been the first landing of the stairs in the Victorian property’s original layout.

Old hot water cylinder location, floor to be lowered to make new bathroom

Sited in Caterham, Surrey, it would be fair to say that the heating system had been bodged up by the previous owner, along with the electrical work.  Various leaking parts had seen the attention of a silicon mastic gun, including radiator valves.

Our customer rather liked the idea of fitting a new bathroom in the area previously occupied by the hot water cylinder, and this meant lowering the floor, which from our perspective meant;

- a combination boiler

- relocation into the cellar for all the boiler plant

The problem with locating the boiler in the cellar is getting the flue out, and dealing with the boiler expansion relief and condensate water.  There is a boiler available in the UK which has some very flexible flue arrangements which would seem ideal for this application called a Keston, but for reasons we’d rather not go into in this public forum, they are never specified by ‘Hot Water & Central Heating’.

We fitted a Vaillant ecoTEC 837 in the cellar, and used a void area to run the flue to a suitable height for a horizontal discharge.  Gas Safe Register are quite rightly insisting that flues in voids must be able to be visually inspected and suitable arrangements are in place.

New boiler and high temperature lift pump below

The condensate and high temperature emergency discharge from the boiler were handled by a new condensate lifter product specially designed to accept high temperature water, this is unique we believe.  We no longer fit the Vaillant branded condensate lifter because Vaillant UK exclude it from their extended boiler warranty.

A Mainsboost GC450 accumulator was also fitted in the cellar to boost the water flow rate and separate the water supply, as the other 5 flats in the building cause water starvation issues as they are all fed from the same rusty water main around 200 metres long.  The water main here was delivering a very high static pressure, peaks of around 7bar were measured.  A pressure reducing valve was fitted to protect the appliances and provide a uniform performance via the acumulator.

The boiler exhaust was fitted with a Vaillant plume management kit, in white to match the building, as cars often part in the vicinity of the flue outlet, and the mildly acidic condensation could cause damage to paintwork.

New Vaillant boiler flue (in white)

This is another installation example of a situation where it is requested that we fit a new high efficiency boiler to an old chimney stack.

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

Our client had a three storey town house in Beckenham, Kent.  Built in the 1970s, it had been fitted with a Johnson & Starley warm air system from new.

Let the work commence

Now theres’s nothing wrong with warm air heating, and we fit the latest US Lennox condensing units for the more discerning customers.  But in common with many properties of this era, economies had been made with the ductwork, resulting in no direct heating of the third bedroom or bathroom.

Our customer had recently bought the property, and faced the choice of many similar households wondering whether to replace the warm air based boiler for a new one or pull it all out and put in a ‘wet’ radiator system.  It wasn’t practical to extend the warm air ductwork into the unheated area, so we suggested fitting a Vaillant ecoTEC+ 837 combination boiler in the front of the garage.

Nearly finished

We managed to utilise some of the old ducts in the property to conceal the new heating pipework, and lifting flooring elsewhere, resulting in a very neatly finished installation.

New radiator in the kitchen

Pipework detail

The relocation of the heating system meant that a very large cupboard was released in the kitchen, which is never a bad thing!

Insulated pipework inside garage

Our customer was very pleased with the results;

“I just wanted to say a big thank you to Simon and Hot Water Central Heating.  We are very

pleased with the work that’s been carried out – apart from the

radiators (we didn’t have them before) you’d never know the guys had

been here.

Sadly, we’re looking forward to it getting cold so we can test it out.

Happily recommed you to anyone.”

Refurbish a 20 year old condensing boiler?  If you have to read this twice, then you probably haven’t got a Kidd VHE.

Somewhere near Canterbury

Our subject of this blog is a 1990 Kidd Oil Model 1 unit in Canterbury, which had been ’serviced’ in recent years by a contractor who was not familiar with the product, or condensers generally.

The condense drains were all completely blocked and full of shale deposits, causing damage to the upper part of the boiler and casing.  This had probably gone unchecked for a number of years.  As a result, the projected 30 yr lifspan had been cruelly truncated.

Economiser was suffering from not being cleaned

We advised the customer that for the price of a new Grant or Worcester unit – which are well made mass market units – we could refurbish his Kidd boiler.  Having seen the build quality of this unit, and having had 20 years reliable service from it, he opted for the rebuild.

A naked Model 1 and a clothed Tim

A new ‘economiser’ was fabricated by Kidd boilers, together with a new flue.  Although the old boiler was 20 yrs old, the new upper section fitted perfectly, because the design is fundamentally unchanged from its inception in 1981.   To finish the job off, a new Sterling Kidd 40 series oil burner was fitted.

Old flue with blocked condense drain tube

New flue incorporating bends to slow down condensate to prevent splashing in the heat exchanger

We Powerflushed the radiator system, removed some copper based condensate tubing (still in parfect condition after 20 years), and fitted some modern Honeywell programmable thermostat controls in the house.

Our customer was thus equipped with a Kidd boiler virtually the same as a new one, to see him through the next few decades with ‘A’ rated efficiency.

As I often tell our customers, condensing boilers aren’t new technology, that is a myth created by politicians to try to take the credit for energy savings.

Over to the picturesque Sussex town of Horsham, where we have a beautiful listed residence in the protected heritage quarter of the town.

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.