VAILLANT ECOTEC PLUS 637 837 937 GAS VALVE WITH REGULATOR (FROM 2012) 0020148383
VAILLANT ecoTEC plus 637 (2012-CURR). VAILLANT ecoTEC PLUS 637 R6 (2012-CURR). VAILLANT ecoTEC plus 837 (2012-CURR). VAILLANT ecoTEC plus 837 R1 (2012-CURR). VAILLANT ecoTEC plus 937 (2012-CURR). Genuine Vaillant Part Not a cheap Chinese make.