Built around 25 years ago, it was heated by two separate Johnson & Starley warm air heaters, one per floor.  For hot water, a 295 litre direct gas fired AO Smith cylinder was installed upstairs.  There was also a large gas hob and a gas fire.

Johnson & Starley Warm Air and AO Smith Water Heater

When we totalled up the load for all these appliances, it was around 92kW.  This would have been fine, apart for two key problems.  The first is that the property had a standard domestic metered supply, which has a maximum design load of around 64kW.  The second problem was tha the gas meter was located a considerable distance away from all the appliances, in a detached garage, and the pipe from the meter into the house was just 22mm in diameter.

This meant that all the appliances were being supplied with a dangerously low pressure.  All the more remarkable was that the units had been serviced each year, by a CORGI/Gas Safe firm.  The same firm that had installed them 25yrs ago, it transpired.

Our customer was faced with either upgrading the gas supply to a light commercial meter, or making changes in the property to reduce the load and keeping the domestic supply.  Unfortunately, the light commercial meter option involved the excavation of a long drive and a huge bill from the gas supplier.

Having conducted some heat calculations for the property, we realised we could replace the heating and hot water system with a modern high efficiency solution and stay within the maximum load of the existing metered supply.

We specified new Lennox G61MPVT condensing warm air units, to replace the old Johnson & Starley equipment.  The G61MPVT is a US made unit that is simply light years ahead of any other warm air heater in the UK.  Delivering an efficiency in excess of 94%, these gas fired warm air heaters are quiet but have powerful fans, designed for minimal electrical consumption.  The units can work vertically or horizontally, and can direct their airflow upwards or downwards, simply by inverting the heater.

New upstairs installation, Lennox to the left, Trion filter above

We also specified Trion air purification units for each heater. Trion high efficiency electronic air cleaners will collect particles down to .01 microns in size and that includes those hazardous, invisible particles, such as tobacco smoke, atmospheric dust and bacteria and even some viruses. So efficient is the Trion high efficiency electronic air cleaners that up to 99% of airborne impurities that enter the unit are removed.

Dave our ductwork specialist working on a Trion air purifier

We engage a specialist ductwork fabrication and installation company to carry out all our modifications on site, for a professional finish.  Many of our competitors use flexible tubes and duct tape, but this is bodging in our view.

Ductwork prepared for new Lennox heater

For the hot water, we had a bespoke Gledhill Solar ready cylinder built, with a storage capacity of 300 litres.  This has a dedicated gas condensing boiler dedicated to heat it, in this case we specified a Vaillant ecoTEC+ 615 system boiler, which was mounted on a support built by us between the prestressed roof timbers.

New Viallant ecoTEC+ system boiler in loft

A much larger gas supply pipe was needed from the meter to the warm air heaters and the Vaillant gas boiler.  It would not have been practical to run a large 35mm outside diameter pipe through the length of the property, so we suggested the driveway was excavated for a modest length, and the old flueway from the downstairs warm air unit used as a duct to get the pipework into the loft.

New pipe from meter to house

A rigid stainless steel gas pipe called TracPipe was used, which allowed us to run internally and externally with no joints, apart from adjacent to the appliances.  This is inherently safer, and gives less resistance to the flow of gas because there no elbows or restrictive connections.

Driveway reinstated!

Our new gas supply to warm units running inside garage

Our new supply pipe (yellow top right) to house

The entire task took 8 days for 3 men, the job was completed in March 2011.  Our customer was wonderful to work with, tea and coffee was on tap together with some rather nice choccy biscuits.

Downstairs boiler intake/exhaust terminal

The heat distribution is better with the Lennox than the old J&S units, because the fans are more powerful.

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!

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.

Rust, Rust and Rust

The Energysaver was one of Glowworm’s early efforts at a high efficiency boiler.  Like the ill fated Potterton Envoy and Baxi Barcelona, the Energysaver had the lifespan of a prawn sandwich.    Although manufacturers like Archie Kidd had perfected the art of condensing boilers decades earlier, the mass market British boiler industry left their designs to the last minute and used their loyal customer base as a test bed. 

Glowworm was snapped up by Vaillant (a leading German boiler manufacturer) over 5 years ago and the Energysaver model was quickly consigned to history and replaced by European designs.  Meanwhile, 5 or 6 years seems to be about the average lifespan before serious internal deterioration renders an Energysaver beyond economic repair.  A classic example of how ‘Green’ labelled products do not necessarily save the planet.

We now travel to Oxted Surrey, where we had been asked to provide a recommendation for a new boiler.

House in Oxted

Our customer had such a boiler and it was leaking.  Being in no mood to buy another boiler with a short lifespan, and due to the tight location within a kitchen unit, we suggested that a Worcester Ri series replacement would prove more reliable and long lived. 

New boiler in position

As usual, we provided a 5yr parts and labour warranty on the unit, and the primary component (heat exchanger) is covered by Bosch for 10 years.  Their only stipulation is that the boiler should be annually serviced.

Secret location in West Norwood

So here we have our customer property in West Norwood;  it’s a rented property with an old Vokera combination boiler in the basement.

Old boiler

The boiler has been suspended on two pieces of timber, which technically is not allowed, because wall hung boilers should be fitted to non combustible surfaces.

Boiler flue is compromised

The second problem was the boiler flue termination, which had various obstructions around it including a deep window sill, and a water butt.

And the third was the gas supply, which was around 8 metres long, in 15mm pipe, with a significant number of elbows – meaning that the existing boiler was under supplied.

The new boiler almost finished

We removed the boiler and fitted a new 18mm plywood support frame, and faced it with a fire resistant sheet.  The new Vaillant ecoTEC+ 831 boiler was fitted to this.

The gas supply was renewed from the meter in a larger bore tube.

Finally the flue was repositioned away from the window and the water butt, to an adjacent wall.

Old boiler flue removed, new one relocated

The old flue aperture was neatly bricked up.

A Vaillant Variable Termination Kit (VTK) was fitted to the flue, as the nearby property boundary was under 2 metres away.  This product lifts the flue outlet higher, and allows the plume (steam) to be directed away.

The system was powerflushed to remove contaminants from the radiators, Honeywell VT200 thermostatic valves were fitted where necessary, and the control system upgraded to feature the Honeywell CM907 programmable wall thermostat/timer.

This system will be covered by our Vaillant 5 year warranty scheme, until 2014.

Our customer also complained that the boiler regularly ‘locked out’ and never seemed to stop.  We found that the wiring centre had been thrown behind the hot water cylinder, there was no room thermostat, and no pump bypass fitted.  This device if missing, would cause the boiler to overheat.

We cured these faults and then the customer pointed out the drain attached to their Potterton boiler.  this is nemant to discharge into the main sewerage system, and any external pipework is meant to be insulated.

This is what we found;

No trouble taken

If you receive a boiler quote that seems cheaper than most, there is usually a reason, and this installation was a typical example of what to expect.  Faulty wiring, incorrect system design and shoddy workmanship.

The next example is from a pensioner’s house in Kingston, Surrey.  She has a warm air unit that was originally commissioned by her late husband (who had no formal gas training).

She was at pains to describe how there was nothing wrong with it;  however even a cursory glance showed us that the installation was in serious danger of setting the house alight and the flue design would be spilling products of combustion inside the house.

Unfortunately, when I appraised her (being as respectful as possible to her late husband) of these facts, she explained that she had been receiving hospital treatment for carbon monoxide in her bloodstream, but that the doctor had said it was naturally occurring and could not have been caused by her boiler…..!

I tried to explain the problem but she asked me to leave and locked the door behind me.  The only picture I could get was of her flue outlet…

 Hopefully she has now had a new unit fitted.

40 people die from carbon monoxide poisioning due to poorly installed or maintained appliances every year.  No one likes regulations, but unfortunately in our industry it is only too necessary.