• Vaillant ecoMAX .../1 combi and system boilers (1999 – 2001)
• Vaillant ecoMAX pro open vent boilers (2002 – 2006)
• Vaillant ecoMAX .../2 combi and system boilers (2001 - 2006)
• Vaillant ecoTEC plus combi, system and open vent boilers (2005 – 2006)
• Vaillant ecoTEC pro combi boilers (2005 – 2006)

All of the above Vaillant ecoMAX and ecoTEC boilers produced before April 2006, were fitted with a silicon burner door seal between the burner door and main heat exchanger, see figure below.

From April 2006, a new graphite seal was introduced with significant benefits:-

- The graphite seal does not need periodic replacement at the time of normal annual servicing, unlike the original silicon seal.

- The new graphite seal is also designed such that it is not necessary to remove the burner module during annual servicing*.

- Consequently, annual service times for boilers fitted with the graphite seals are reduced.

* The burner module would only need to be removed and inspected should either a combustion analysis or visual inspection of the flame picture indicate the appliance is outside of specification. Note: If the burner door is removed for any reason a new graphite seal must be always be fitted.

In 2007, Vaillant issued a service reminder to installers strongly recommending them to fit a new graphite seal when doing the normal annual servicing on the boilers listed above.

  

If any of the boilers on the above list (i.e. those produced before April 2006 and still fitted with a silicon seal) have not been serviced for an extended period, there is the possibility that the silicon seal could degrade over time to the point where heat can escape into the boiler inner casing. If left for an extended period without attention, this can result in distortion of the burner door and / or plastic components internally within the boiler being damaged through overheating.

Following a small number of recent cases involving Vaillant boilers which had not been serviced for an extended period and where the silicon seal had not been replaced as recommended, Vaillant has worked together with CORGI to prepare the CORGI Bulletin TB242 which was issued on 4th March 2009. The bulletin further reinforces the message to installers to ensure that the annual service checks are properly carried out, and to pay particular attention to the burner door. If the installer believes that an older silicon type seal is fitted, Vaillant strongly recommend that the seal should be replaced with a new graphite seal. The approach to be taken by the installer when one of the above boilers is identified is outlined in further detail in TB242.

Ordering graphite seals
Seals are avalable to order as spare parts through national and independent merchants across the UK, using the following article number: 0020038679