New Vaillant 6 series system boiler in loft, Nutfield
December 12th, 2008
Our customer premises
Our client, an independent church ministry, occupy a building in the Nutfield region of Surrey, near Redhill.
Their original boiler was a Potterton Suprima, a model which enjoyed high sales between approximately 1995 and 2004. Unfortunately, it also featured regularly on BBC’s Watchdog programme, due to some alleged design defects which result in the circuit boards needing frequent replacement.
This unit failed for a diffferent reason. The Suprima can have a long flue run, if the optional Potterton twin pipe system is employed. Our customer had such an installation, running from the airing cupboard mounted boiler, through a large loft space, to a vertical flue terminal on the rear side of the pitched roof.
Condensation had formed inside the flue (which a Potterton Suprima is not constructed to deal with, as it is a non condensing boiler), which had run back down the pipe inside the combustion area of the boiler, where it was trapped, and rotted the casing. Result, a total write off.
Having checked our Potterton archive, the flue was installed correctly by the original builder, so this appears to be another Suprima instance of an under developed and tested product being introduced to market. Luckily, very few Suprimas were equipped with this type of twin pipe flue system, but if yours was, you may want to get it checked over before a dangerous situation develops.
We recommended that the new boiler, a Vaillant ecoTEC+ 624, was sited in the roof space. The new boiler is a high efficiency condensing type, and needs a drain attached, which was not available in the airing cupboard.
Vaillant system boiler in loft space
The installed system of radiators used microbore plumbing, so was unable to be Powerflushed clean due to the frictional resistance of the pencil thin pipe. Heating companies have been known to connect their powerflush machines to microbore, but it is utterly pointless, because the flow of water through the radiators is so small it does not have an agitating or cleansing effect.
To help protect the boiler from dirt and rust contamination in the old pipework, we fitted the latest ‘TwinTech’ from Adey systems, this captures ferrous material with a magnetic rod, and non ferrous detritus in a filter. This unit, seen in purple underneath the boiler, is the new upgraded version of the old Adey ‘Magnaclean’ filter.
The flue was run through the loft space (shown temporarily supported here) to a new vertical terminal on the roof.
Vaillant flue inside loft area
Scaffolding was needed here due to the roof having no apex but a hidden flat top, so roof ladders could not be used.
The neatest jobs are the ones you can't see
New Honeywell 907 thermostat in hall
Inside a Vaillant 6 series ecoTEC+
View with control panel down
