Viessmann is asking engineers to correct a potential problem concerning UK boilers found to pose a possible safety risk but it is more than a year after similiar actions were taken to correct the problem in Germany, China, the US and Canada.
A technical problem concerning the O-ring of the gas valve used in specific boiler models was discovered in 2008 by the German boiler manufacturer, resulting in replacement action in the four countries in October 2008. However the UK was left without warnings of the potential gas leak risk, until November 2009.

The products affected are:

· Vitodens 200/222, model years 1999 to 2005, inclusive
· Vitodens 300/333, model years 2004 to 2006, inclusive
· Vitocrossal 300 up to 66 KW, model years 2003 to 2006, inclusive
· Spare part - gas valve, model years 1999 to 2006, inclusive


On November 16, 2009, Viessmann sent a letter to 2,400 UK merchants and installers to inform them of the issue. An excerpt from the letter states: 'we wish to inform you without prejudice that a technical issue has been identified by our quality control system. The O-ring of the gas valve, manufactured by Kromschroeder and used in various gas-fired condensing boilers of the Vitodens and Vitocrossal models, could become brittle after an extended period of operation if working under unfavourable conditions. This could possibly allow an escape of gas and as a precautionary measure we have decided to replace all the O-rings at risk.'

The affected boilers were produced between 1999 and 2006. The company stressed its current portfolio of boilers are not affected. Viessmann is now keen to trace all 3,000 boilers in the UK that it believes may pose a possible safety risk.

Viessmann stated: 'It could potentially become a safety issue, since the O-ring could become brittle after being in operation for years. To avoid any complications, Viessmann is interested to solve this matter proactively'.

When heatingandventilating.net asked why the UK replacement action did not take place a year ago at the same time as the action in the US and Canada subsidiary, Germany and China, a spokesman for Viessmann said: 'In total, this affects approx. 3,000 boilers in the UK, i.e. the volume of products affected is very limited'.

The company added: 'The replacement of the O-ring is a purely pre-emptive and voluntary measure, and with products having been sold and installed in 26 countries worldwide no incidents have been reported. When the issue became known to Viessmann during 2008 a risk analysis for the affected markets was carried out in due diligence and an order of priority established for approaching them.

'Viessmann UK started research immediately in order to trace the affected boilers and to establish the necessary procedures suitable for the UK heating market and in compliance with local standards. Tracing the affected boilers was a laborious and time consuming process, mainly due to the various routes to market via merchants and installers for the different affected products and the fact that sales date back as far as 1999.

'As soon as all the data was compiled Viessmann Ltd approached merchants and installers in the UK. Thanks to the meticulous preparations Viessmann Ltd were able to provide detailed information about the affected boilers supplied, thus laying the foundation for a quick, safe and professional handling of the Kromschroeder Field Action'.

INSTALLER FAQs

Who can I contact if I have questions regarding this field action?

In terms of claims and processing, contact the number provided [below]. For technical assistance, you can also contact Viessmann technical staff based in Telford.

To whom can I pass details about delivery addresses for affected boilers?

Please provide these details to the project office, which coordinates all the activities related to this field action.

What if the installer incurs more costs than compensated by the flat rate of £60+VAT?

The replacement of the O-ring should take place during the annual service of the boiler. Therefore, no additional costs should be incurred. The mentioned rate [£60+VAT] is the max. installer fee that will be paid.

What does the installer have to do to claim?

He has to replace the O-ring and confirm this on the confirmation card provided with the spare O-rings. This card must be send to the project office along with the invoice for his labour.

If the installer runs out of spare O-rings, where can he get new ones?

He needs to contact the project office by phone and ask for the required quantity. They will instantly be sent.

The Viessmann hotline contact details are:

Kromschroeder Project Office
Hotline phone: 0800 0113624
Hotline fax: 0800 0113625
Email: Aktion-Dichtring@viessmann.com