Exchange electronics Combi 6/6E with control unit CP plus. For the exchange the return of the old electronics to Truma is necessary. For doing that, please contact the specialized trade. So the exchange will happen: Customer has a Combi heating with grey casing. The dealer controls the retrofit desire and makes an offer: CP plus and retrofit plate ( 299.-- inkl.vat/Status Feb 2014) plus additional working time for the installation ( approx. 45 minutes). The customer place an order, the dealer transfers the serial nummer/ model description to Truma Service. Truma Service delivers the plate ( for the moment without charge), if the dealer returns the old changed plate as well as the receipt within 4 weeks after the order to Truma Service. Otherwise Truma charges the plate for the gross spare part price. The dealer installs the new plate and removes the old one. To benefit from the free of charge offer for the exchange plate, he will return the old plate as well as the receipt back to Truma Service within 4 weeks after the order took place.