Summary of legal proceedings by Truma (UK) who tried to stop production of a replica of the popular Carver Cascade 2 water heater. Updated February 2009. Now obsolete!

This page comprises principally extracts from a Patent Office document. It appears to confirm that UK caravan industry 'folklore' about Truma and its high prices and restricted supply of spare parts is justified.

In particular, Truma seem to adopt an environmentally damaging policy of denying spare parts availability or continued production at a reasonable price thus pushing consumers into buying new complete heater units when a few minor repairs to old ones could have sufficed. The environmental arguments in favour of repair are set out elsewhere on this website.

The Patent Office seem entirely happy with a situation in which spare parts for consumer products are only made available for 5 years (or less) when the proper 'environmentally responsible' lifetime of many well engineered units could easily exceed 20 years. Given maintenance and repair by competent persons, the life of Carver heaters could probably exceed that of most caravans. The twin consequences of the business operations and policies of Truma are that caravanners have to pay exorbitant prices and the environment is damaged by equipment being scrapped and new equipment being manufactured well before the old needed to have been replaced.

As of 2005, new Carver Cascade 2 'lookalike' heaters were manufactured in the UK - the patents originally granted to Carver and taken over by Truma having then expired. As of October 2005, the price including UK carriage was 325. Many of the parts can be used as spares for earlier Carver Cascade 2 heaters. However, some industry sources say that (as of 2009) there are reliability issues with these copies - which are said to be made in China (unconfirmed). Certainly, as of 2009, many spare parts for older Carver cascade heaters are becoming very difficult to find. For example, the earlier (larger diameter) tie bars are not obtainable, nor are replacement cylinders. Truma could easily enough manufacture these - even as a service to the industry and the environment - but they would prefer to sell you a new Ultrastore heater and an adapter plate to fit to the old Cascade mounting points than a few parts to repair a Cascade unit. The Ultrastore units are apparently quite reliable but very costly - around 500.


Extracts from the Patent Office document (emphasis added):

"Prior to its acquisition by Truma, Carver appears to have been a successful company which had produced and sold water heaters according to the patents over a number of years. It is not disputed that.... Carver came to dominate the UK market for this type of appliance. However, following the take-over of Carver by Truma, Truma ceased the manufacture of (Carver) heaters and adopted a policy of promoting in their place the products emanating from its German parent...

Central to this case is the fate of all the existing Carver heaters which had been sold before the withdrawal of the product. When these break down or wear out, they need to be repaired or replaced. Although Truma do not make this model any more, the opponents (Truma) say that if customers want to replace old Carver heaters with new ones to the same design, there are enough in stock to satisfy any demand which might arise. However Truma's own design of heater can also be supplied as a replacement. This is not the same as the Carver heater but can be fitted in its place with the aid of a special adapter plate.

Swansea (the applicants) base their submission that there remains a considerable demand among users of old Carvers for new heaters of similar design, and that Truma are not willing to meet this demand. Swansea would therefore like a license to exploit the Carver patents themselves through the manufacture and supply of complete heaters and spare parts. Swansea has previously approached Carver for a licence to do this but was refused.

There is no dispute that the patented product has been taken out of production, or that Truma, as a matter of business policy, does not wish to see the patent being exploited by anybody else. It has been alleged, and not denied, that Truma's business objective in taking over Carver was to eliminate the hitherto dominant Carver product from the UK market and use its control of the Carver patent to keep the field free for its own design.

Moreover, a manufacturer is fully entitled to withdraw products, including patented products, from the market in favour of new ones that it may wish to bring forward. However, in this kind of situation a patentee is not entitled to use its patent as a tool for preventing competition against its new product if there is a continuing unsatisfied demand for the patented technology. This is precisely the kind of abuse that the compulsory license provisions of the Act are intended to combat.

Carver introduced a water heater (the "Cascade One") in the early 1980's suitable for installation in touring caravans. This was subsequently developed and further models were brought out. By the time of Carver's acquisition by Truma in 1999, Carver "dominated" the UK market with their heaters fitted to new caravans by many UK manufacturers. ...up to 90% of the 24,000 caravans sold every year for the 15 years prior to 1999, as well as many horse boxes catering trailers and motor homes, were fitted with Carver heaters.

... following the take-over of Carver and the cessation of the manufacture of the Carver range, spare parts had become difficult or in some cases impossible to obtain, which had led to difficulties for servicing of existing heaters. In response to this situation, he (the applicant) approached Truma with a request for a licence to manufacture Carver water heaters and spares, but was told that "under no circumstances did [Truma] want the Carver water heater or spares back on the market".

.... the Truma heater ... which is being offered as a replacement for Carvers is inferior in many respects, and as a result of this situation the need for Carver owners to maintain or replace (or repair?) their old heaters is not being met.

Another explanation, ... which I (the Patent Office official ) consider to be the more likely, is that dealers are holding on to their remaining stocks because they prefer to "cannibalise" them as a source of spare parts. They are prepared to supply complete units to customers who really want them, but in practice not very many customers are prepared to pay the prices (up to 500) that are being asked."


The full Patent Office document was available in pdf format. http://www.patent.gov.uk/patent/legal/decisions/2004/o17004.pdf


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